Patent Publication Number: US-2016240273-A1

Title: Hybrid nuclear-hydro power plant

Description:
FEDERALLY SPONSORED RESEARCH 
     Not Applicable 
     SEQUENCE LISTING OR PROGRAM 
     Not Applicable 
     BACKGROUND AND FIELD OF THE INVENTION 
     This invention relates to electrical power generation in general, and more specifically describes a method and apparatus for economically converting nuclear energy (heat) into water potential energy by utilizing nuclear reactors coupled directly with water pumps to lift water from downstream to upstream of hydro-power plant. Upon demand, the stored water is used to generate electricity by the hydroelectric power plant. This way, water can be recycled and used more than once to generate electricity, and the reactor can be operated at a steady state power level. 
     BACKGROUND DESCRIPTION OF PRIOR ART 
       
     
       
         
           
               
             
               
                   
               
               
                 References 
               
               
                 U.S. Patent Documents 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 4,177,019 
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                 Chadwick 
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                 4,166,222 
                 1979 
                 Hanley 
                 290/55 
               
               
                   
                 6,023,105 
                 Feb. 8, 2000 
                 Youssef 
                 290/54 
               
               
                   
                 6,073,445 
                 Jun. 13, 2000 
                 Johnson 
                  60/512 
               
               
                   
                   
               
            
           
         
       
     
     Hydro energy has been used in different parts of the world for centuries before the birth of Christ, and since the late 19 th  century to generate electricity by utilizing the potential energy of an elevated body of water. 
     In the context of hydro-power plant operations, a major concern is the availability of a consistent supply of reservoir water to run the turbo generators. Many such dams are underutilized with seasonal variation as inflow deficit limits the availability of water as potential energy. Recent analytical modeling of water availability and prediction of other water usages are a complex and developing science. 
     One approach to the problem of storing energy and then utilizing the stored energy as electricity is by pumped-storage systems. These are typically designed to utilize a combination generator-motor to pump the water from a lower reservoir to an upper reservoir by drawing electricity from the grid during low electricity demand periods then reversing the function of the pumps to act as generators to convert the potential energy of the upper reservoir into electricity at higher demand periods. This energy can come from a variety of electrical sources, including other hydro-electric stations, fossil fueled generators, wind, or even conventional nuclear power generators. 
     Many problems associated with the current methods of creating energy to lift water in such systems exist. The electricity used to lift the stored water may or may not be locally generated or may not be naturally dependable or reliable as in the case of solar or wind power. If a conventional nuclear power plant is utilized, the energy has been converted from nuclear heat into steam, then into mechanical motion with turbines, then generating electricity. As the efficiency in each step is less than unity, therefor the multiplication of all the conversion factors leads to unavoidable losses. 
     Some previous inventions include heat sources that utilize combustion of fossil fuels, yet the main problem with that approach is the production of combustion gasses including large amounts of carbon dioxide and other pollutants. 
     If a utility wishes to build a new nuclear power plant, and pump water utilizing an electric-powered pump into a storage reservoir, such conventional nuclear power plants not only include the reactor heat source, but also the “Balance of Plant” required to generate electricity. This overly complicates the design, licensing, and operations of such power plants, and does not avoid the multiple step conversion power losses. 
     SUMMARY OF THE INVENTION 
     The present invention is specified in view of the aforesaid problems in the related art. 
     With the introduction of this visionary concept, the existing investment in the hydro-power plant can be maximized without the need to balance the various demands on precious water resources. 
     Tail water recycling via a collection pond or reservoir with pumps directly connected to a nuclear reactor eliminates many of these concerns. The envisioned simplified nuclear reactor system need not generate electricity as do conventional nuclear power plants, yet the heat from the reactor may be directly utilized to generate pumping power to lift water. Additional benefits from such a system are that the reactor need not follow the electricity loads or demands, as the source of energy is decoupled from the generation of electricity by the large potential energy capacity of the reservoir. This allows for much simplified design, licensing, and ease of operating the reactor in a steady state mode. 
     Intrinsically safe nuclear reactors (ISNR) and intrinsically safe small modular reactors differ from conventional nuclear fission reactors in that the design is more elegantly simple affording lower costs and ease of operation. A Bi-Stable reactor would be ideal for this application. 
     In one application of this invention, one or more water pumps, each powered directly by heat from a nuclear reactor, lift water from down-stream of a river, stream, or pond to upstream of a dam at which a hydro-power plant is installed. Intrinsically safe small modular reactors are ideally suited to provide pumping heat in an incremental manner in such an application. Upon demand, the lifted water is again used to generate electricity by the hydro-power plant. A weir or small dam may be constructed across the river or stream downstream of the heat-powered pump, to create a reservoir or pool from which the water can be drawn and recycled. 
     Past Disclosure of Concept: 
     Also disclosed is a method for incorporating an intrinsically safe nuclear fission reactor in a pumped storage system that comprises: (a) specifying an initial reactor design with a pumping unit and desalination unit; (b) specifying an energy storage reservoir and (c) a hydro-electric plant, thus creating a “Hybrid Nuclear Power System” (see System Flow Chart, FIG. 4, of Application number 20110255650) 
     Combinations of multiple intrinsically safe nuclear reactors, pumping units, and conventional hydro-electric power stations all utilizing a common large energy storage reservoir, comprise a “Hybrid Nuclear Power System” is also disclosed and claimed. 
     From March 2010 
     FIG. 4 is a diagram of the components, one of which is the intrinsically safe reactor, in relation to other major components utilized to generate electricity, desalinate seawater, or provide district heat, in a “Hybrid Nuclear Power System”, according to the teachings of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Illustrative and present embodiments of the invention are shown in the accompanying drawings in which: 
         FIG. 1  “Overview of Invention”, is an elevation view of a representation showing the components of a Hybrid Nuclear-Hydro Power Plant according to one embodiment of the present invention; 
         FIG. 2  “Heat-Powered Pump”, is a sectional view of a heat-powered pumping chamber of said system showing the two cycles of operation: filling and lifting, according to one embodiment of the present invention. 
     
    
    
     REFERENCE NUMERALS USED IN DRAWINGS 
     
         
         
           
             A Nuclear Reactor as Heat Source 
             B Heat Powered Pump 
             C Dam with High Reservoir 
             D Hydro-Electric Generation Facility 
             E Low Reservoir 
               1  High Heat Supply Conduit 
               2  Waste Heat Return Conduit 
               3  Reverse Penstock 
               4  Dam 
               5  Penstock 
               6  Hydro-Electric Power Station 
               7  Discharge Tailpipe 
               8  Water Inlet 
               9  Watersource, Sea or Aquifer 
               10  Salt Water Input 
               11  Cooling Conduit 
               12  Fresh Water Conduit 
               13  Brine Water Output 
               21  Pumping Chamber Wall 
               22  Chamber Cover, Valve, Equipment, and Conduit Support Ring 
               23  Discharge Check Valve Assembly 
               24  Inlet Check Valve Assembly 
               25  Vaporizer Assembly 
               26  Discharge Pipe 
               27  Vapor Exit Valve and Conduit 
               28  Working Fluid Supply and Return Conduits 
           
         
       
    
     However, before proceeding with the description, it should be noted that the various embodiments shown and described herein are exemplary only and are not intended to represent the extent to which the present invention may be utilized. Indeed, the systems and methods described herein could be readily applied to any of a wide range of Hybrid Nuclear-Hydro Power System designs, as would be obvious to persons having ordinary skill in the art after having become familiar with the teachings provided herein. Consequently, the present invention should not be regarded as limited to the particular Hybrid Nuclear-Hydro Power System and example configurations shown and described herein. 
     DETAILED DESCRIPTION 
     Referring now to  FIG. 1 : “Overview of Invention”, one embodiment of an Hybrid Nuclear-Hydro Power Plant may comprise a Nuclear Reactor A to provide heat to a Heat-Powered Pump B which takes water from a Low Reservoir E and lifts the water to a High Reservoir C where a Hydro-Electric Power Station D uses the potential energy of the reservoir to generate electricity. In one embodiment of a Hybrid Nuclear-Hydro Power Plant may utilize the waste heat from the Heat-Powered Pump B to provide low-value heat to a Desalination Plant, thus returning the coolant back to the Nuclear Reactor A after making fresh water, which may be deposited into the Low Reservoir E or otherwise distributed. 
     When the Nuclear Reactor A is turned on, and sufficient heat is achieved, a conduit  1  conveys the high value heat to a Heat Powered Pump B, which utilized inlet water  8  from the Low Reservoir E, via a created difference in pressure, lifting the water through a Reverse Penstock  3  into the High Reservoir C to be stored as potential energy. 
     When required, a Hydro-Electric Power Station D removes the water via a Penstock  5  from the High Reservoir C supported by a Dam  4 , and converts the potential energy stored in the elevated water to kinetic energy via gravitational acceleration to generate electricity  6  output to the Utility Grid or other electrical loads. 
     Referring now to  FIG. 2 : “Heat-Powered Pump”, one embodiment of an Hybrid Nuclear-Hydro Power Plant may comprise a Heat-Powered Pump B which takes water from a Low Reservoir via a water inlet where the water flows via gravity from the pond or tailwater downstream of the hydro-electric plant discharge. 
     In one embodiment of such a pump, the pump comprises a Pumping Chamber Wall  21  wherein the water to be lifted falls through an Inlet Check Valve Assembly  24  until the pumping chamber is filled. During the filling cycle of operation the inlet water level is rising and the previous vapor (steam) is being released through a plurality of Vapor Exit Valves and Conduits  27  which may pass through another machine(s) or turbine(s) to recover additional energy from the steam (not depicted yet known to those practitioners of the art). As the water rises to maximum level the Inlet Check Valves close and then a set of energy transfer devices, in one embodiment, comprises a generally toroidal-shaped set of coils, a Vaporizer Assembly  25  in which the high value heat from the Nuclear Reactor A has passed from the reactor into the pump via a plurality of Working Fluid Supply and Return Conduits  28  and transfers the heat via radiation and conduction into the water. In one embodiment, the water floods the Vaporizer Assembly  25 , and when a sufficient amount of heat has transferred into the water, the sensible heat rises and then latent heat is absorbed to vaporize the water creating steam. Depending upon the design requirements for volume and pressure to lift the water, a variety of sizes and volumes of components of the Vaporizer Assembly  25  are envisioned. As the pressure rises in the pumping chamber the water level remains constant until the design pressure has been achieved. At that time the lifting force opens the Discharge Check Valve Assembly  23  and allows for the water to pass upwards through the Discharge Pipe, with an “Entry Flow Enhancing Shape”  26 , out of the pumping chamber past the Chamber Cover, Valve, Equipment, and Conduit Support Ring  23  and exits into the Reverse Penstock, flowing up towards the High Reservoir. 
     When the discharge cycle has completed the pressure in the pumping chamber lowers, and when it is less than the pressure inside the Discharge Pipe  26  the Discharge Check Valve  23  closes and the flow stops. The control system (not depicted, yet known to practitioners in the art) opens the Vapor Exit Valve(s)  27  and allows the pressurized steam to exit through the exit conduit, and lowers the pressure inside the pumping chamber, thus allowing the filling cycle to begin again. 
     In one embodiment of the invention, a plurality of Heat Powered Pumps work out of phase with each other to provide a more or less constant flow of water into the High Reservoir, and provide a more or less consistent demand on the Nuclear Reactor heat source by lifting the water to the High Reservoir via a manifold discharge into the Reverse Penstock to be stored as potential energy. 
     As a component of a “Hybrid Nuclear-Hydro Power System”, the Intrinsically Safe Nuclear Reactor, (ISNR), may provide high value, high temperature heat to another energy conversion component (water/steam/water or other vapor cycle thermal to mechanical energy system, or process load; which converts the high value heat output from the Intermediate Heat Exchanger (IHX) portion of the reactor, to a conventional or legacy electric plant to create electricity and distribute it to the community, and waste heat from the energy conversion component may also utilize low value heat to provide district heating and cooling, and to desalinate seawater or purify other watersources. 
     Additionally, as the total “Hybrid Nuclear-Hydro Power System” is modular in nature, multiple reactors or heat sources could provide heat energy to multiple Heat Powered Pump units that could utilize the same reservoir with multiple reactor-pumps and hydro-electric plants to increase overall performance and operational redundancy of the total system. An additional embodiment of this invention is for use with cascading water reservoirs, each with smaller hydro-power electrical generators for local use. 
     In another embodiment of the invention, nuclear reactor heat powered steam turbine(s) coupled to conventional mechanical or centrifugal pumps may be utilized as part of a Hybrid Nuclear-Hydro Power System. 
     In summation, then, because persons having ordinary skill in the art could readily select from one or several component configurations of the design described herein, after having become familiar with the teachings of the present invention, the present invention should not be regarded as limited to varying any one or combination of the heat sources, pumping units, process heat loads, or hydro-power components described herein. 
     Present invention should not be regarded as limited to any kind of working heating fluid. 
     Present invention should not be regarded as limited to any kind of reservoir storage fluid. 
     Present invention should not be regarded as limited to any scale of power output. 
     Present invention should not be regarded as limited to any scale of energy storage. 
     Present invention should not be regarded as limited to any particular type of renewable heat source or combination of heat sources. 
     Having herein set forth some embodiments of the present invention, it is anticipated that suitable modifications can be made thereto which will nonetheless remain within the scope of the invention. The invention shall therefore only be construed in accordance with the specific included claims.