Power plant with motorless feed pump

Abstract

The present invention relates to a novel method for operating a thermal power plant or refrigeration cycle in which a spent low pressure working fluid is recycled to a high pressure vaporizer using temperature control within a heat exchanger instead of employing a working fluid feed pump. While the non-steady process is similar to a Rankine cycle, technically, it is no longer a Rankine cycle.

1 . A thermal power system comprising: 
 a vaporizer for vaporizing a thermal fluid at a high pressure having a vaporizer output supplying high pressure thermal fluid;    an expansion device 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 also supplying mechanical power and/or refrigeration for cooling an enclosed space;    a 1 st  heat exchanger connected to said output of said expansion device for cooling and condensing said low pressure thermal fluid, producing condensed thermal fluid, said 1 st  heat exchanger also supplying a predetermined reserve capacity for receiving said condensed thermal fluid, having an output controlled by a 1 st  valve;    a 2 nd  heat exchanger in selective thermal communication with a heat sink and a thermal energy source, said 2 nd  heat exchanger positioned to accept said condensed thermal fluid from said 1 st  heat exchanger by gravity when said 1 st  valve is opened, said 2 nd  heat exchanger including at its output a 2 nd  valve;    said vaporizer positioned and connected to said 2 nd  valve to accept said condensed thermal fluid by gravity from said 2 nd  heat exchanger when said 2 nd  valve is opened;    whereby said 1 st  valve, 2 nd  valve, and 2 nd  heat exchanger may be operated to permit intermittent passage of said condensed thermal fluid from said 1 st  heat exchanger to said vaporizer without causing substantial reduction of said pressure in said vaporizer.    
   
   
       2 . A method of operating a power plant comprising the steps of: 
 vaporizing a thermal fluid to provide a high pressure thermal fluid in a vaporizer;    expanding said thermal fluid to produce useful mechanical power and/or refrigeration effect for cooling an enclosed space and a low pressure thermal fluid;    cooling, condensing and accumulating said thermal fluid in a 1 st  heat exchanger to provide a condensed thermal fluid;    intermittently passing, using gravity, said accumulated condensed thermal fluid through a 1 st  valve to a 2 nd  heat exchanger by opening said 1 st  valve;    closing said 1 st  valve;    heating said accumulated condensed thermal fluid in said 2 nd  heat exchanger;    opening a 2 nd  valve;    passing said accumulated condensed thermal fluid from said 2 nd  heat exchanger through said 2 nd  valve, using gravity, to said vaporizer;    closing said 2 nd  valve;    and cooling said 2 nd  heat exchanger until the pressure in said 2 nd  heat exchanger is not substantially higher than the pressure of the condensed thermal fluid accumulating in 1 st  heat exchanger.    
   
   
       3 . A refrigeration system comprising: 
 a vaporizer for vaporizing a thermal fluid at a high pressure having a vaporizer output supplying high pressure thermal fluid;    a venturi device in fluid communication with said vaporizer output for expanding said high pressure thermal fluid and providing a low pressure thermal fluid at a venturi output of said expansion device, said expansion device also supplying suction pressure at a venturi suction input;    an evaporator in fluid connection with said venturi suction input, said evaporator also having an evaporator input, for cooling an enclosed space;    a 1 st  heat exchanger in fluid connection to said venturi output of said venturi device for cooling and condensing said low pressure thermal fluid, said 1 st  heat exchanger also in fluid connection with said evaporator input, said 1 st  heat exchanger also supplying a predetermined reserve capacity for receiving said condensed thermal fluid, having an output controlled by a 1 st  valve;    a 2 nd  heat exchanger in selective thermal communication with a heat sink and a thermal energy source, said 2 nd  heat exchanger positioned to accept said condensed thermal fluid from said 1 st  heat exchanger by gravity when said 1 st  valve is opened, said 2 nd  heat exchanger including at its output a 2 nd  valve;    said vaporizer positioned and connected to said 2 nd  valve to accept said condensed thermal fluid by gravity from said 2 nd  heat exchanger when said 2 nd  valve is opened;    whereby said 1 st  valve, 2 nd  valve, and 2 nd  heat exchanger may be operated to permit intermittent passage of said condensed thermal fluid from said 1 st  heat exchanger to said vaporizer without causing substantial reduction of said pressure in said vaporizer.    
   
   
       4 . A method of operating a refrigeration system comprising the steps of: 
 vaporizing a thermal fluid to provide a high pressure thermal fluid in a vaporizer;    expanding said thermal fluid in a venturi device to produce both a low pressure thermal fluid at a venturi output and a suction pressure at a venturi suction input;    evaporating a thermal fluid from an evaporator through said venturi suction input, inducing a refrigeration effect within said evaporator for cooling an enclosed space;    cooling, condensing and accumulating said thermal fluid in a 1 st  heat exchanger to provide a condensed thermal fluid;    passing a portion of said accumulated condensed thermal fluid to said evaporator to maintain a presence of condensed thermal fluid in said evaporator;    intermittently passing, using gravity, said accumulated condensed thermal fluid through a 1 st  valve to a 2 nd  heat exchanger by opening said 1 st  valve;    closing said 1 st  valve;    heating said accumulated condensed thermal fluid in said 2 nd  heat exchanger;    opening a 2 nd  valve;    passing said accumulated condensed thermal fluid from said 2 nd  heat exchanger through said 2 nd  valve, using gravity, to said vaporizer;    closing said 2 nd  valve;    and cooling said 2 nd  heat exchanger until the pressure in said 2 nd  heat exchanger is not substantially higher than the pressure of the condensed thermal fluid accumulating in 1 st  heat exchanger.    
   
   
       5 . A refrigeration system comprising: 
 a vaporizer for vaporizing a thermal fluid at a high pressure having a vaporizer output supplying high pressure thermal fluid;    a converging/diverging nozzle in fluid communication with said vaporizer output for expanding said high pressure thermal fluid and providing a below ambient temperature low pressure thermal fluid at an output of said converging/diverging nozzle;    a 3 rd  heat exchanger in fluid communication with said output of said convergent/divergent nozzle for cooling an enclosed space, having a 3 rd  heat exchanger output;    a 1 st  heat exchanger in fluid communication with said output of said 3 rd  heat exchanger for cooling and condensing said low pressure thermal fluid, producing condensed thermal fluid, said 1 st  heat exchanger also supplying a predetermined reserve capacity for receiving said condensed thermal fluid, having an output controlled by a 1 st  valve;    a 2 nd  heat exchanger in selective thermal communication with a heat sink and a thermal energy source, said 2 nd  heat exchanger positioned to accept said condensed thermal fluid from said 1 st  heat exchanger by gravity when said 1 st  valve is opened, said 2 nd  heat exchanger including at its output a 2 nd  valve;    said vaporizer positioned and connected to said 2 nd  valve to accept said condensed thermal fluid by gravity from said 2 nd  heat exchanger when said 2 nd  valve is opened;    whereby said 1 st  valve, 2 nd  valve, and 2 nd  heat exchanger may be operated to permit intermittent passage of said condensed thermal fluid from said 1 st  heat exchanger to said vaporizer without causing substantial reduction of said pressure in said vaporizer.    
   
   
       6 . A method of operating a refrigeration system comprising the steps of: 
 vaporizing a thermal fluid to provide a high pressure thermal fluid in a vaporizer;    expanding said thermal fluid through a converging/diverging nozzle to produce a below ambient temperature low pressure thermal fluid;    passing said below ambient temperature low pressure thermal fluid through a 3 rd  heat exchanger for cooling an enclosed space;    cooling, condensing and accumulating said thermal fluid in a 1 st  heat exchanger to provide a condensed thermal fluid;    intermittently passing, using gravity, said accumulated condensed thermal fluid through a 1 st  valve to a 2 nd  heat exchanger by opening said 1 st  valve;    closing said 1 st  valve;    heating said accumulated condensed thermal fluid in said 2 nd  heat exchanger;    opening a 2 nd  valve;    passing said accumulated condensed thermal fluid from said 2 nd  heat exchanger through said 2 nd  valve, using gravity, to said vaporizer;    closing said 2 nd  valve;    and cooling said 2 nd  heat exchanger until the pressure in said 2 nd  heat exchanger is not substantially higher than the pressure of the condensed thermal fluid accumulating in 1 st  heat exchanger.    
   
   
       7 . A refrigeration system comprising: 
 a vaporizer for vaporizing a thermal fluid at a high pressure having a vaporizer output supplying high pressure thermal fluid;    an expander in fluid communication with said vaporizer output for expanding said high pressure thermal fluid and providing a below ambient temperature low pressure thermal fluid at an output of said converging/diverging nozzle;    a 3 rd  heat exchanger in fluid communication with said output of said convergent/divergent nozzle for cooling an enclosed space, having a 3 rd  heat exchanger output;    a 1 st  heat exchanger in fluid communication with said output of said 3 rd  heat exchanger for cooling and condensing said low pressure thermal fluid, producing condensed thermal fluid, said 1 st  heat exchanger also supplying a predetermined reserve capacity for receiving said condensed thermal fluid, having an output controlled by a 1 st  valve;    a 2 nd  heat exchanger in selective thermal communication with a heat sink and a thermal energy source, said 2 nd  heat exchanger positioned to accept said condensed thermal fluid from said 1 st  heat exchanger by gravity when said 1 st  valve is opened, said 2 nd  heat exchanger including at its output a 2 nd  valve;    said vaporizer positioned and connected to said 2 nd  valve to accept said condensed thermal fluid by gravity from said 2 nd  heat exchanger when said 2 nd  valve is opened;    whereby said 1 st  valve, 2 nd  valve, and 2 nd  heat exchanger may be operated to permit intermittent passage of said condensed thermal fluid from said 1 st  heat exchanger to said vaporizer without causing substantial reduction of said pressure in said vaporizer.    
   
   
       8 . A method of operating a refrigeration system comprising the steps of: 
 vaporizing a thermal fluid to provide a high pressure thermal fluid in a vaporizer;    expanding said thermal fluid through an expander to produce a below ambient temperature low pressure thermal fluid;    passing said below ambient temperature low pressure thermal fluid through a 3 rd  heat exchanger for cooling an enclosed space;    cooling, condensing and accumulating said thermal fluid in a 1 st  heat exchanger to provide a condensed thermal fluid;    intermittently passing, using gravity, said accumulated condensed thermal fluid through a 1 st  valve to a 2 nd  heat exchanger by opening said 1 st  valve;    closing said 1 st  valve;    heating said accumulated condensed thermal fluid in said 2 nd  heat exchanger;    opening a 2 nd  valve;    passing said accumulated condensed thermal fluid from said 2 nd  heat exchanger through said 2 nd  valve, using gravity, to said vaporizer;    closing said 2 nd  valve;    and cooling said 2 nd  heat exchanger until the pressure in said 2 nd  heat exchanger is not substantially higher than the pressure of the condensed thermal fluid accumulating in 1 st  heat exchanger.