Patent Publication Number: US-11643993-B2

Title: Heat engine with magnetically linked pistons

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 63/168,563, which was filed on Mar. 31, 2021. The entire content of the foregoing provisional application is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to heat engines. More specifically, the present disclosure relates to heat engines including magnetically coupled and/or linked pistons that provide improved efficiency and effectiveness in operation. 
     BACKGROUND 
     A variety of engine designs are used in the industry to convert heat to work, or work to heat transfer. Such engines can use the process of compression, heat addition, expansion of a working fluid, and/or heat rejection. As an example, some traditional engines use a mechanical compressor and expander to perform the thermodynamic cycles. However, based on the design of traditional engines, the process can lack efficiency and effectiveness, resulting in significant energy losses. 
     SUMMARY 
     In accordance with embodiments of the present disclosure, an exemplary heat engine is provided that includes magnetic or electromagnetically driven and linked pistons that significantly improve the efficiency and effectiveness of engine operation. As used herein, the term “heat engine” refers to a heat engine, a heat pump, a thermal energy conversion device, combinations thereof, or the like. The pistons traverse mechanical cylinder chamber topologies in a magnetically coupled and/or linked manner to continuously and cyclically perform the compression and expansion cycles, providing for an increase in the thermal to work conversion performance. Operation of the exemplary heat engine can further economic viability and climate impact reductions in a variety of technology sectors. 
     In accordance with embodiments of the present disclosure, an exemplary heat engine is provided. The heat engine includes a pipe that defines a continuous internal path. The pipe includes a first pipe section and a second pipe section. The heat engine includes a first piston disposed within the first pipe section. The heat engine includes a second piston disposed within the second pipe section. The first and second pistons are magnetically linked to travel along the continuous internal path of the pipe. 
     In some embodiments, the first pipe section includes a first end and an opposing second end, and the second pipe section includes a first end and an opposing second end. In some embodiments, the first end of the first pipe section is connected to the second end of the second pipe section, and the first end of the second pipe section is connected to the second end of the first pipe section. In some embodiments, the heat engine can include a third pipe section including a first end and an opposing second end. In such embodiments, the first end of the first pipe section can be connected to the second end of the third pipe section, and the first end of the second pipe section can be connected to the second end of the third pipe section. The first, second and third pipe sections thereby define the continuous internal path. 
     The heat engine can include an external driving mechanism configured to generate electromagnetic forces to drive the magnetically linked travel of the first and second pistons along the continuous internal path of the pipe. In some embodiments, the external driving mechanism can include coil windings disposed around the first and second sections of the pipe. 
     In some embodiments, the first pipe section can define a first loop of the pipe and the second pipe section can define a second loop of the pipe. In such embodiments, the first and second loops traverse along a shared (or substantially shared) plane. In some embodiments, the first pipe section can define a loop of the pipe and the second pipe section can define a helical pathway around the loop formed by the first pipe section. In such embodiments, the helical pathway can define a longer pathway than a pathway of the loop. In such embodiments, during the magnetically linked travel of the first and second pistons along the continuous internal path of the pipe, a speed of the first or second piston traveling through the helical pathway is greater than a speed of the first or second piston traveling through the loop. 
     In one complete cycle, the first piston travels along the continuous internal path through the first pipe section, into the second pipe section, through the second pipe section, and back to the first pipe section. Simultaneously, in the one complete cycle, the second piston travels along the continuous internal path through the second pipe section, into the first pipe section, through the first pipe section, and back to the second pipe section. The first and second pistons remain magnetically linked during travel through the respective first and second pipe sections. 
     The pipe can be fabricated from a non-magnetic material. The first and second pistons can be fabricated from a magnetic material. In some embodiments, ferrofluid can be disposed within the continuous internal path of the pipe. The ferrofluid can provide a dynamic seal and/or bearing effect between an inner surface of the pipe and the respective first and second pistons. The magnetically linked travel of the first and second pistons along the continuous internal path of the pipe achieves continuous (or substantially continuous) compression and expansion cycles. In some embodiments, the first pipe section can define a diameter greater than a diameter of the second pipe section. In some embodiments, the heat engine can include a hot heat exchanger fluidly connected to the first pipe section at or near the first and opposing second ends. In some embodiments, the heat engine can include a cold heat exchanger fluidly connected to the second pipe section at or near the first and opposing second ends. 
     In accordance with embodiments of the present disclosure, an exemplary method of operating a heat engine is provided. The method includes driving travel of a first piston and a second piston of a heat engine along a continuous internal path of a pipe. The heat engine includes the pipe that defines the continuous internal path. The pipe includes a first pipe section and a second pipe section. The heat engine includes the first piston disposed within the first pipe section. The heat engine includes the second piston disposed within the second pipe section. The method includes maintaining the first and second piston magnetically linked to each other during travel along the continuous internal path of the pipe. 
     In one complete cycle, the first piston travels along the continuous internal path through the first pipe section, into the second pipe section, through the second pipe section, and back to the first pipe section. Simultaneously, in the one complete cycle, the second piston travels along the continuous internal path through the second pipe section, into the first pipe section, through the first pipe section, and back to the second pipe section. The first and second pistons remain magnetically linked during travel through the respective first and second pipe sections. 
     Other features and advantages will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To assist those of skill in the art in making and using the disclosed heat engine, reference is made to the accompanying figures, wherein: 
         FIG.  1    is a top diagrammatic view of an exemplary heat engine in accordance with the present disclosure. 
         FIG.  2    is a perspective diagrammatic view of the exemplary heat engine of  FIG.  1   . 
         FIG.  3    is a top, cross-sectional diagrammatic view of the exemplary heat engine of  FIG.  1   . 
         FIG.  4    is a perspective, cross-sectional diagrammatic view of the exemplary heat engine of  FIG.  1   . 
         FIG.  5    is a cross-sectional diagrammatic view of the exemplary heat engine of  FIG.  1   . 
         FIG.  6    is a cross-sectional diagrammatic view of the exemplary heat engine of  FIG.  1   , including piston pathways. 
         FIG.  7    is a perspective diagrammatic view of piston pathways of the exemplary heat engine of  FIG.  1   . 
         FIG.  8    is a top diagrammatic view of an exemplary heat engine in accordance with the present disclosure. 
         FIG.  9    is a perspective diagrammatic view of the exemplary heat engine of  FIG.  8   . 
         FIG.  10    is a top, cross-sectional diagrammatic view of the exemplary heat engine of  FIG.  8   . 
         FIG.  11    is a perspective, cross-sectional diagrammatic view of the exemplary heat engine of  FIG.  8   . 
         FIG.  12    is a cross-sectional diagrammatic view of the exemplary heat engine of  FIG.  8   , including piston pathways. 
         FIG.  13    a perspective diagrammatic view of piston pathways of the exemplary heat engine of  FIG.  8   . 
         FIG.  14    is a top diagrammatic view of an exemplary heat engine in accordance with the present disclosure. 
         FIG.  15    is a perspective diagrammatic view of the exemplary heat engine of  FIG.  14   . 
         FIG.  16    is a top, cross-sectional diagrammatic view of the exemplary heat engine of  FIG.  14   . 
         FIG.  17    is a perspective, cross-sectional diagrammatic view of the exemplary heat engine of  FIG.  14   . 
         FIG.  18    is a cross-sectional diagrammatic view of the exemplary heat engine of  FIG.  14   . 
         FIG.  19    is a perspective diagrammatic view of piston pathways of the exemplary heat engine of  FIG.  14   . 
         FIG.  20    is a perspective diagrammatic view of an exemplary heat engine in accordance with the present disclosure. 
         FIG.  21    is a perspective view of an exemplary piston in accordance with the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The exemplary heat engines discussed herein provide significant advantages to operational efficiency and effectiveness as compared to traditional heat engines. Although discussed herein as a heat engine, it should be understood that the exemplary systems can be configured or reconfigured as a heat engine, a heat pump, or a thermal energy conversion device. In some embodiments, one or more of the pipe sections or components can be combined to form a machine capable of acting simultaneously as a heat engine and a pump. The heat engine includes magnetically coupled and/or linked pistons that continuously operate compression and expansion cycles in an efficient manner. The heat engine thereby defines a magnetically linked free piston machine, a more effective heat engine, allowing a closer following of the thermodynamic ideal. One of the enabling kinematic principles used by the heat engine can be separate but magnetically or electromagnetically linked mechanically advantaged free pistons traversing in closely following parallel (or substantially parallel) cylinder chambers. The pistons can continuously and unidirectionally revolve in contiguous cylinder bore loops acting in one section of the heat engine as a compressor and in another section of the heat engine as an expander. Heat addition or rejection can occur by a large conductive exchange surface area from significantly elongated piston cylinders of unrestricted stroke length. The heat engine can form a closed cycle machines (or a substantially closed cycle machine) with highly pressurized working gas or an open cycle designs of internal combustion with air induction and exhaust. Different processes of mechanical advantage can be used by the heat engine to achieve expansion chamber work driving compression. In some embodiments, a differential bore diameter (where the cylinder chamber compression bore is dimensioned smaller than the expansion bore) can be used, e.g., with low expansion ratios. In some embodiments, a straight fixed compression cylinder chamber bore can be surrounded by a helical screw-like expansion cylinder bore path, which can be used with, e.g., large expansion ratios. 
     The magnetically linked free-piston can be used to expand the possibilities in engine functionality advancement. Near or quasi-isothermal compression and expansion without loss compounding stages can be achievable in low power-to-weight ratio designs, enhancing work output by more closely following thermodynamic ideals. The exemplary heat engine can exhibit characteristics similar to the Brayton cycle of high rate and continuous non-cyclical power output advantages without the high cost and low effectiveness of traditional turbine systems in less than several MW sizes. Recuperation or regeneration can be executed as the heat flow nature in the heat engine is counter current flowed. Unidirectional operation of the working fluid mass with the elimination of thermal short circuit reverse flow can further reduce losses that traditional reciprocating engines may suffer. 
     The heat engine can emphasize the heat exchanger performance with fully integrated gas working compressor and expander pistons, an inherent linear transiting magnetic flux for electrical generation, and a remarkable heat-to-electricity efficiency given the delta-T utilized. The free-piston magnetic design can also be used as a new type of internal combustion machine suitable for high power-to-weight ratio applications. The exemplary heat engine design provides numerous energy use advancement opportunities in solar, geothermal, waste heat recovery, thermal storage-to power, and possibly transportation. In some embodiments, the heat engine design can assist in reductions of energy-related emissions, including greenhouse gases. 
     The heat engine is capable of overcoming the Curie temperature barrier of permanent magnetism, which is a limitation of the heat engine&#39;s working temperature. As a magnetic piston travels in the heat engine, the piston can arrive at a mean temperature based on the transit length of the heat exchange chambers. Increased cold side length exchange can allow higher delta-Ts by lower mean magnetic piston temperature. In some embodiments, the heat engine can be based on an exclusively electromagnetic principle. Extreme temperatures suitable particularly for an internal combustion machine can be achievable as electromagnetic inductive coils to not suffer magnetic flux output degradation, with the conductive resistance increasing instead. Electromagnetic induction can serve the engine&#39;s workings as compared to permanent magnets, while also providing far greater magnetic flux strength. The heat engine design can minimize the magnetic field air gap while balancing insulating hot and cold sections. Creative engineering solutions in the three-dimensional back iron magnetic flux guide(s) can be used. The heat engine design further overcomes the difficulty in achieving magnetic flux density cross-section for high power outputs through plural cylinder path flux linking geometries. 
       FIGS.  1 - 7    are diagrammatic top, perspective, cross-sectional and detailed views of an exemplary heat engine  100  (e.g., a differential bore magnetic heat engine system). The heat engine  100  provides for continuous expansion and compression cycles, resulting in higher power-to-weight ratio, output and efficiency. The heat engine  100  includes a single pipe  102  continuously (or substantially continuously) formed to define an internal path along which pistons  104 ,  106 ,  108  travel to continuously perform the expansion and compression cycles. The pipe  102  is separated into three distinct sections—a first pipe section  110  (e.g., a hot pipe, a hot major exterior pipe, or the like), a second pipe section  112  (e.g., a cold pipe, a cold minor exterior pipe, or the like), and an intermediary pipe section  114  (e.g., an intermediate pipe, an expansion exterior pipe, or the like). 
     The pipe sections  110 - 114  are each formed in loops and are connected at their respective ends to define the continuous internal path. As discussed herein, a linear pathway refers to a pathway that generally extends along the same plane (e.g., along a horizontal plane). Although illustrated as extending along substantially linear pathways, it should be understood that the pipe sections  110 - 114  could be configured to extend in non-linear pathways. The heat engine  100  includes a first transition  116  between the first pipe section  110  and the intermediary pipe section  114 , a second transition  118  between the intermediary pipe section  114  and the second pipe section  112 , and a third transition  120  between the second pipe section  112  and the first pipe section  110 . 
     Each transition  116 - 120  defines a tapered section based on the difference in diameters of the respective pipe sections  110 - 114 . In particular, the first pipe section  110  defines a substantially linear, curved pathway with a first end (e.g., at or near the first transition  116 ) and a second opposing end (e.g., at or near the third transition  120 ). The second pipe section  112  defines a substantially linear, curved pathway with a first end (e.g., at or near the third transition  120 ) and a second opposing end (e.g., at or near the second transition  118 ). The intermediary pipe section  114  defines a substantially linear, curved pathway with a first end (e.g., at or near the second transition  118 ) and a second opposing end (e.g., at or near the first transition  116 ). The intermediary pipe section  114  generally travels along the same plane as the first and second pipe sections  110 ,  112 , except for one portion of the intermediary pipe section  114  that passes over the first and second pipe sections  110 ,  112  to connect with the second transition  118 . 
     The first pipe section  110  defines a first outer diameter and an internal opening  122  having a first inner diameter. In some embodiments, the first pipe section  110  can include an internal jacket space  124  between the internal opening  122  and the outer surface of the first pipe section  110  to provide an insulating effect for reduction in temperature losses of the working fluid. The second pipe section  112  defines a second outer diameter and an internal opening  126  having a second inner diameter. In some embodiments, the second pipe section  112  can include an internal jacket space  128  between the internal opening  126  and the outer surface of the second pipe section  112 . The intermediary pipe section  114  defines a third outer diameter and an internal opening  130  having a third inner diameter. In some embodiments, the intermediary pipe section  114  can include a solid wall  132  between the internal opening  130  and the outer surface of the intermediary pipe section  114 . In some embodiments, the solid wall  132  can be replaced with a jacket space similar to the jacket spaces  124 ,  128  of the first and second pipe sections  110 ,  112 . The jacket spaces  124 ,  128  can receive a heat transfer fluid pumping therethrough to impair a hot and cold temperature gradient throughout the heat engine  100 . A thermal exchange can thereby occur in the pipe sections  110 - 114  to the enclosed working gas and/or working fluid, with the reverse occurring in a heat pump configuration. 
     The first inner diameter of the first pipe section  110  (and the outer diameter of the first pipe section  110 ) is dimensioned greater than the second inner diameter of the second pipe section  112  (and the outer diameter of the second pipe section  112 ) and the third inner diameter of the intermediary pipe section  114  (and the outer diameter of the intermediary pipe section  114 ). The third inner diameter of the intermediary pipe section  114  (and the outer diameter of the intermediary pipe section  114 ) is dimensioned greater than the second inner diameter of the second pipe section  112  (and the outer diameter of the second pipe section  112 ). The first pipe section  110  thereby defines the greatest internal pathway diameter, the intermediary pipe section  114  defines the next greatest internal pathway diameter, and the second pipe section  112  defines the smallest internal pathway diameter. In some embodiments, second pipe section  112  internal diameter can be half of the internal diameter of the first pipe section  110  diameter, and the intermediary pipe section  114  internal diameter can be ¾ of the first pipe section  110  diameter. However, it should be understood that the dimensional relationships of the pipe section  110 - 114  diameters (e.g., the diameter ratios) could be varied for optimization of the heat engine  100  operation. The difference in diameters results in a tapered configuration of the respective transitions  116 - 120 . In some embodiments, the heat engine  100  could be designed with only the first pipe section  110  and the second pipe section  112  connected by respective transitions, without including the intermediary pipe section  114 . However, the intermediary pipe section  114  can provide for smoother and more efficient expansion of the working fluid. 
     The heat engine  100  includes a hot heat exchanger  134  fluidly connected at one end to the first pipe section  110  at or near the transition  116  (e.g., downstream of the transition  116 ), and fluidly connected at an opposing end to the first pipe section at or near the transition  120  (e.g., upstream of the transition  120 ). The heat engine  100  includes a cold heat exchanger  136  fluidly connected at one end to the second pipe section  112  at or near the transition  120  (e.g., downstream of the transition  120 ), and fluidly connected at an opposing end to the second pipe section  112  at or near the transition  118  (e.g., upstream of the transition  118 ). 
     The heat engine  100  includes one or more coil windings  138  positioned around the pipe sections  110 - 114 . The coil windings  138  can be, e.g., wire coil electric linear generator/alternator windings fabricated from copper, or the like. The windings  138  can be used as exciter windings by receiving current from an external source (e.g., AC or DC current) to generate electromagnetism to drive movement of each of the pistons  104 - 108 . In some embodiments, the windings  138  can be used or act as a power take-off, an extraction of magnetic piston&#39;s kinetic energy of moving the magnetic flux to electricity, exciter and/or induction windings, or the like. The pipe sections  110 - 114  can be fabricated from a non-magnetic material and/or non-conductive material (e.g., an insulator in the electric sense) to prevent eddy current interference with the pistons  104 - 108  and windings  138 . Although three coil windings  138  are shown in the figures for simplicity, in some embodiments, the heat engine  100  can include coil windings  138  positioned along the entire or substantially along the entire length of the pipe sections  110 - 114  to provide the electromagnetic force, power take-off and/or extraction to electricity for the pistons  104 - 108  along the entire route within the pipe sections  110 - 114 . 
     The pistons  104 - 108  can be fabricated from a magnetic material. Based on the magnetic material of the pistons  104 - 108  and the electromagnetic force and/or induction generated by the windings  138 , the pistons  104 - 108  remain magnetically aligned and magnetically coupled (and/or linked) relative to each other as the pistons  104 - 108  move along their respective pathways between the pipe sections  110 - 114 . For example, as shown in  FIGS.  3 - 7   , the piston  104  travels along pathway  140 , the piston  106  travels along pathway  142 , and the piston  108  travels along pathway  144 . However, the pathways  140 - 144  form a continuous path that travels through each of the pipe sections  110 - 114 . Therefore, the piston  104  initially travels along pathway  140 , which transitions to pathway  142 , which further transitions to pathway  144 , and reconnects with pathway  140 . Each piston  104 - 108  therefore travels along each of the pathways  140 - 144  during the continuous cycle operation of the heat engine  100 . Due to the magnetic coupling of the pistons  104 - 108  relative to each other, as the pistons  104 - 108  travel along each of the pathways  140 - 144 , the pistons  104 - 108  remain substantially aligned relative to each other. For example, the leading edge of the pistons  104 - 108  can remain substantially aligned relative to each other. 
     Ferrofluid can be used inside of the heat engine  100  to provide a dynamic seal around the pistons  104 - 108  as the traverse at least some of the pathways  140 - 144 . The ferrofluid can include a magnetic iron fluid having iron nanoparticles suspended in a fluid. When placed around a magnetic material, the ferrofluid can substantially surround the magnet and acts as a bearing surface around the magnet. The ferrofluid can thereby act as a bearing surface around at least a portion of the magnetic pistons  104 - 108 . The fluid nature of the ferrofluid creates a dynamic seal that can adjust as the diameters of pipe sections  110 - 114  change in the heat engine  100 . The pistons  104 - 108  can each be dimensioned substantially equally, and further define a cylindrical configuration with a diameter configured to create a seal with the ferrofluid in the second pipe section  112  and the intermediary pipe section  114 . The internal opening diameter of the first pipe section  110  can be dimensioned large enough to avoid a complete seal with the pistons  104 - 108  (even with the dynamic nature of the ferrofluid), to allow for movement of the working gas around the pistons  104 - 108 . In some embodiments, rather than ferrofluid, an expandable rubber magnetic or electromagnetic piston (e.g., the piston of  FIG.  21   ) can be used to achieve the dynamic sealing. In some embodiments, another suitably dynamic material for the piston  104 - 108  could be implemented. 
     In operation, working fluid or gas is introduced into the heat engine  100 . The heat engine  100  can include one or more working charge ports to add the working gas charge or pre-charge to the pipe sections  110 - 114 . The working fluid or gas can be, e.g., helium, air, any gas, or a phase change of water, organic fluids, HCFCs, or the like. Electric current can be applied to the coil windings  138  to generate the electromagnetic forces to initiate movement of the pistons  104 - 108  within their respective pipe sections  110 - 114 . Hot and/or cold thermal transfer fluid flows in the respective pipe sections  110 - 114  can also assist in movement of the pistons  104 - 108 . The pistons  104 - 108  each move in the same clockwise or counterclockwise direction, depending on the layout of the heat engine  100 . In the first pipe section  110 , the working gas is heated and the piston  104 - 108  does not seal the internal opening walls. Instead, the working gas is advanced sufficiently by the piston  104 - 108  inside of the first pipe section  110  towards the intermediary pipe section  114 . In the intermediary pipe section  114 , the ferrofluid creates a dynamic seal around the piston  104 - 108  relative to the inner opening walls and expansion of the working gas is achieved. 
     Expansion of the working gas helps create an internal force within the heat engine  100  to drive movement of the pistons  104 - 108 . The pistons  104 - 108  are thereby driven by the expansion force (and maintain their magnetic linking) as a heat engine  100 . In particular, the single piston of the pistons  104 - 108  traversing the intermediary pipe section  114  is propelled by the expansion force occurring within the heat engine  100 , and the piston in the intermediary pipe section  114  further propels the piston in the second pipe section  112  to impart the compression force while the working fluid is cooled. The piston located in the pipe section  110  follows the path freely as the working gas is heated from the hot pipe walls. Each piston  104 - 108  therefore cyclically performs the respective roles in each of the pipe sections  110 - 114  as the pistons  104 - 108  traverse the internal pathways of each of the pipe sections  110 - 114 . 
     As a heat pump configuration, electricity is consumed and imparted through the coil windings  138 , causing a moving magnetic field motivation of the magnetic pistons  104 - 108 , and forming a temperature gradient in the jacket space heat exchange spaces (as the heat pump is reverse from a heat engine operation). The forces acting on the pistons  104 - 108  are also reverse in the heat pump configuration as compared to the heat engine configuration. The intermediate diameter of the intermediary pipe section  114  accommodates incremental expansion of the working gas between the first and second pipe sections  110 ,  112  to ensure efficiency of the heat engine  100  operation. As the piston  104 - 108  progresses into the second pipe section  112 , the ferrofluid creates a dynamic seal around the piston  104 - 108  relative to the inner opening walls, the working gas is cooled and compression occurs. In particular, the working gas is cooled from the pipe walls via the jacket space flowing thermal transfer fluid, allowing for compression to occur in a heat engine configuration, or heat to be rejected as compression occurs in the flowing thermal transfer fluid in the heat pump configuration. 
     Based on the magnetic coupling of the pistons  104 - 108 , each of the respective pistons  104 - 108  is either passing through the first pipe section  110  to progress the heated working gas, passing through the intermediary pipe section  114  to create expansion of the working gas, or passing through the second pipe section  112  to cause or create the condition of incremental compression of the working gas. In particular, the working fluid or gas is heated from the pipe walls via the jacket space flowing thermal transfer fluid, allowing for expansion to occur in the heat engine configuration, or heat addition of the working fluid as expansion occurs, removing heat from the thermal transfer fluid in the heat pump configuration. Said in a different way, the working fluid or gas is heated and cooled, allowing for improved expansion and compression to occur in the heat engine configuration. Alternatively, heat addition and rejection to the working fluid can occur as expansion and compression occurs, moving heat from the thermal transfer fluid in the heat pump configuration. The heat engine  100  is therefore continuously operating the compression and expansion cycles. 
       FIGS.  8 - 13    are diagrammatic top, perspective, cross-sectional and detailed views of an exemplary heat engine  200  (e.g., a helical magnetic heat engine system). The heat engine  200  can be substantially similar to the heat engine  100 , except for the distinctions discussed herein. Rather than three pipe sections that define substantially linear pathways along the same plane, the heat engine  200  includes two pipe sections that define substantially linear pathways along the same plane, and an intermediary pipe section that creates a helical pathway around the substantially linear pathways of the other pipe sections. The helical pathway increases the distance traveled by the piston within the intermediary pipe section (and the speed at which the piston travels), while maintaining each of the pistons substantially aligned based on the magnetic coupling of the pistons relative to each other. 
     In particular, the heat engine  200  includes a single pipe  202  continuously (or substantially continuously) formed to define an internal path along which pistons  204 ,  206 ,  208  travel to continuously perform the expansion and compression cycles. The pipe  202  is separated into the first pipe section  210  (e.g., a hot pipe, a hot major exterior pipe, or the like), a second pipe section  212  (e.g., a cold pipe, a cold minor exterior pipe, or the like), and an intermediary pipe section  214  (e.g., an intermediate pipe, an expansion exterior pipe, or the like). 
     The pipe sections  210 ,  212  are formed in loops and are connected to each other or the intermediary pipe section  214  to define the continuous internal path. The pipe sections  210 ,  212  extend along a substantially linear pathway along the same plane (e.g., along a horizontal plane), except for portions of the pipe sections  210 ,  212  that overlap or bend to facilitate connection between the pipe sections  210 - 214 . The intermediary pipe section  214  defines a substantially helical pathway encircling the pipe sections  210 ,  212  except during the transition between the pipe section  210  to the intermediary pipe section  214 , and the transition between the intermediary pipe section  214  to the pipe section  212 . The pathway formed by the helical configuration is therefore longer than the linear pathway of the pipe sections  210 ,  212 . 
     The heat engine  200  includes tapered transitions  216 ,  218  between the first pipe section  210  and the intermediary pipe section  214 , and between the first and second pipe sections  210 ,  212 . In some embodiments, a transition can be provided between the intermediary pipe section  214  and the second pipe section  212 . The tapered transitions  216 ,  218  accommodate the difference in diameters of the pipe sections  210 - 214 . The first pipe section  210  defines a first outer diameter and an internal opening  222  having a first inner diameter. In some embodiments, the first pipe section  210  can include an internal jacket space  224  between the internal opening  222  and the outer surface of the first pipe section  210  to provide an insulating effect for reduction in temperature losses of the working fluid. In some embodiments, a heat transfer fluid can be pumped through the jacket spaces  224 ,  228  to impart a hot and/or cold temperature gradient throughout the heat engine  200 . Such gradient could occur in the corresponding pipe sections  210 - 224  for thermal exchange to the enclosed working gas and/or working fluid. The reverse can occur in a heat pump configuration. The second pipe section  212  defines a second outer diameter and an internal opening  226  having a second inner diameter. In some embodiments, the second pipe section  212  can include an internal jacket space  228  between the internal opening  226  and the outer surface of the second pipe section  212 . The intermediary pipe section  214  defines a third outer diameter and an internal opening  230  having a third inner diameter. In some embodiments, the intermediary pipe section  214  can include a solid wall  232  between the internal opening  230  and the outer surface of the intermediary pipe section  214 . In some embodiments, the solid wall  232  can be replaced with a jacket space similar to the jacket spaces  224 ,  228  of the first and second pipe sections  210 ,  212 . 
     The relationship of the diameters of the pipe sections  210 - 214  can be similar to the diameters of the pipe sections  110 - 114  of the heat engine  100 . In particular, The first inner diameter of the first pipe section  210  (and the outer diameter of the first pipe section  210 ) is dimensioned greater than the second inner diameter of the second pipe section  212  (and the outer diameter of the second pipe section  212 ) and the third inner diameter of the intermediary pipe section  214  (and the outer diameter of the intermediary pipe section  214 ). The third inner diameter of the intermediary pipe section  214  (and the outer diameter of the intermediary pipe section  214 ) is dimensioned greater than the second inner diameter of the second pipe section  212  (and the outer diameter of the second pipe section  212 ). The first pipe section  210  thereby defines the greatest internal pathway diameter, the intermediary pipe section  214  defines the next greatest internal pathway diameter, and the second pipe section  212  defines the smallest internal pathway diameter. 
     The heat engine  200  includes a hot heat exchanger  234  fluidly connected at opposing ends to the first pipe section  210  at or near the transition  216  and at or near the transition  218 . The heat engine  200  includes a cold heat exchanger  236  fluidly connected at opposing ends to the second pipe section  212  at or near the transition  218  and downstream from the transition of the intermediary pipe section  214  to the second pipe section  212 . The heat engine  200  includes one or more coil windings  238  for activating and driving the pistons  204 - 208 . In some embodiments, the coil windings  238  can be used for electric power extraction via a moving magnetic flux induction. The heat engine  200  can include windings  238  positioned along the entire or substantially entire loop of the pipe sections  210 - 214 . The pistons  204 - 208  remain magnetically coupled as they travel along respective pathways  240 ,  242 ,  244 , ensuring the pistons  204 - 208  are substantially aligned relative to each other in their respective pipe sections  210 - 214 . For example, the leading edge, trailing edge, or central point of the pistons  204 - 208  can be substantially aligned relative to each other along the same plane (e.g., vertical, lateral plane). The piston  204 - 208  traveling along the helical pathway  244  therefore travels a greater distance at a greater speed than the pistons  204 - 208  traveling along the substantially linear pathways  240 ,  242 . However, during the continuous operation of the heat engine  200 , each piston  204 - 208  travels along the pathways  240 - 244  in sequential order. Ferrofluid (or the piston of  FIG.  21   ) can be used to create the dynamic seal between the pistons  204 - 208  and the inner walls of the pathways  240 - 244 . 
     In operation, working fluid or gas is introduced into the heat engine  200 . Current can be applied to the coil windings  238  to generate the electromagnetic forces to initiate movement of the pistons  204 - 208  within the respective pipe sections  210 - 214 . The pistons  204 - 208  each move in the same clockwise or counterclockwise direction, with one of the pistons  204 - 208  traversing in the clockwise or counterclockwise direction along the helical path. In the first pipe section  210 , the working gas is heated and the piston  204 - 208  inside of the first pipe section  210  does not seal the internal opening walls. Instead, the working gas is advanced sufficiently by the piston  204 - 208  inside of the first pipe section  210  towards the intermediary pipe section  214 . In the intermediary pipe section  214 , the ferrofluid creates a dynamic seal around the piston  204 - 208  relative to the inner opening walls and expansion of the working gas is achieved. Expansion of the working gas helps create or cause an internal force within the heat engine  200  to drive movement of the pistons  204 - 208 . The intermediate diameter of the intermediary pipe section  214  accommodates gradual expansion of the working gas between the first and second pipe sections  210 ,  212  to ensure efficiency of the heat engine  200  operation. The helical pathway of the intermediary pipe section  214  increases the length of the pathway and speed at which the piston of the pistons  204 - 208  traversing the intermediary pipe section  214  travels, resulting in an increase in expansion achievable by the heat engine  200 . 
     As the piston  204 - 208  progresses into the second pipe section  212 , the ferrofluid creates a dynamic seal around the piston  204 - 208  relative to the inner opening walls, the working gas is cooled and incremental compression occurs. In particular, the working fluid or gas is heated from the pipe walls via the jacket space flowing thermal transfer fluid, allowing for expansion to occur in the heat engine configuration, or heat addition of the working fluid as expansion occurs, removing heat from the thermal transfer fluid in the heat pump configuration. Said in a different way, the working fluid or gas is heated and cooled, allowing for improved expansion and compression to occur in the heat engine configuration. Alternatively, heat addition and rejection to the working fluid can occur as expansion and compression occurs, moving heat from the thermal transfer fluid in the heat pump configuration. Based on the magnetic coupling and/or linking of the pistons  204 - 208 , each of the respective pistons  204 - 208  is either passing through the first pipe section  210  to progress the heated working gas, passing through the intermediary pipe section  214  to create expansion of the working gas, or passing through the second pipe section  212  to create incremental compression of the working gas. The heat engine  200  is therefore continuously operating the compression and expansion cycles. 
       FIGS.  14 - 19    are diagrammatic top, perspective, cross-sectional and detailed views of an exemplary heat engine  300  (e.g., an internal combustion helical heat engine system). The heat engine  300  can be substantially similar to the heat engines  100 ,  200 , except for the distinctions discussed herein. Rather than including three pipe sections, the heat engine  300  includes two pipe sections—a first pipe section that defines a substantially linear pathway, and a second pipe section that defines a substantially helical pathway around the first pipe section. Instead of a hermetically (or quasi-hermetically charged) enclosed system for the working gas (as is done in the heat engines  100 ,  200 ), the heat engine  300  includes features for introduction of outside air into the heat engine  300  and exhausting combustion gases. 
     In particular, the heat engine  300  includes a single pipe  302  continuously (or substantially continuously) formed to define an internal path along which pistons  304 ,  306  travel to continuously perform the expansion and compression cycles. The pipe  302  is separated into the first pipe section  310  and a second pipe section  312 . The pipe sections  310 ,  312  are formed in loops and are connected to each other at respective opposing ends to define the continuous internal path. The pipe section  310  extends along a substantially linear pathway along the same plane (e.g., along a horizontal plane). The pipe section  312  defines a substantially helical pathway encircling the pipe section  310  except during the transition between the pipe section  312  and the pipe section  310 . The pathway formed by the helical configuration is therefore longer than the linear pathway of the pipe section  310 . 
     The outer and inner diameters of the pipe sections  310 ,  312  can be dimensioned substantially equally and, therefore, the heat engine  300  does not include tapered transitions. In particular, the pipe section  310  defines an outer diameter and an internal opening  322  having a first inner diameter, and the pipe section  312  defines an outer diameter and an internal opening  326  having a second inner diameter substantially equal to the first inner diameter. The pipe sections  310 ,  312  can include an internal jacket space (or a solid wall) between the respective internal openings  322 ,  326  to provide an insulating effect for reduction in temperature losses of the working fluid. In some embodiments, insulation of one or more partial or full sections of the pipe sections  310 ,  312  could be used. In some embodiments, if a jacket space is used, a thermal transfer fluid exchange could be used for a reheat, cooling, regeneration, or intercooling effect or process. 
     At the connection between the pipe sections  310 ,  312 , the heat engine  300  includes an air intake induction/exhaust section  346  including a plurality of openings into the internal passage of the pipe sections  310 ,  312 . The section  346  allows for intake or exhaust of outside air into the internal passage of the pipe sections  310 ,  312  to mix outside air with the working gas during the compression and expansion cycles. The heat engine  300  includes a high pressure fuel spray injector  348  and an adjacently positioned spark plug ignition/igniter  350 . The injector  348  and igniter  350  can be disposed downstream from the connection between the first and second pipe sections  310 ,  312 . In some embodiments, the section  346  can be at a first connection between the pipe sections  310 ,  312 , and the injector  348  and igniter  350  can be at the other connection between the pipe sections  310 ,  312 . 
     In some embodiments, no hot or cold heat exchangers are included in the heat engine  300 . In some embodiments, the heat engine  300  can include a heat exchangers. The heat engine  300  includes coil windings  338  for generating the electromagnetic force to activate and drive the pistons  304 ,  306 . The heat engine  300  can include windings  338  positioned along the entire or substantially entire loop of the pipe sections  310 ,  312 . The pistons  304 ,  306  remain magnetically coupled as they travel along respective pathways  340 ,  342 , with the magnetic coupling maintaining the pistons  304 ,  306  substantially aligned relative to each other along the same plane (e.g., vertical, lateral plane). The piston  304 ,  306  traveling along the helical pathway  342  therefore travels a greater distance at a greater speed than the piston  304 ,  306  traveling along the substantially linear pathway  340 . However, during the continuous operation of the heat engine  300 , each piston  304 ,  306  travels along the pathways  340 ,  342  in sequential order. 
     In operation, working fluid or gas is introduced into the heat engine  300 . Current can be applied to the coil windings  338  to generate the electromagnetic forces to initiate movement of the pistons  304 ,  306  within the respective pipe sections  310 ,  312 . In some embodiments, the coil windings  338  can provide electric power extraction via a moving magnetic flux induction. The pistons  304 ,  306  each move in the same clockwise or counterclockwise direction, with one of the pistons  304 ,  306  traversing in the clockwise or counterclockwise direction along the helical path. In the first pipe section  310 , the working gas or fluid is compressed and may be cooled, while in the second pipe section  312 , the working gas is heated and expanded. Outside air is introduced by the ports or openings in the section  346  during the continuous operating cycle. Air is compressed by the magnetically linked pistons  304 ,  306  imparting a mechanical advantage (e.g., machine inclined plane principle) from the helical hot combustion gas section. As the cycle&#39;s magnetically linked pistons  304 ,  306  continue in the repetitive loop, the hot combustion gases are expelled or exhausted from the ports of the section  346 . In some embodiments, a naturally liquid or gas fuel and spark can be provided by the injector  348  and igniter  350 , depending on the desired compression ratio. In some instances, a permanent physical magnet can lose all magnetism at high temperatures, which is known as the Curie temperature. Such loss of magnetism can be addressed by the exemplary piston shown in  FIG.  21   . 
       FIG.  20    is a diagrammatic perspective view of an exemplary heat engine  400 . The heat engine  400  can be substantially similar to the heat engines  200 ,  300 , except for the distinctions noted herein. Rather than including a helical intermediary pipe section and substantially linear first and second pipe sections (e.g., heat engine  200 ), or a single substantially linear first pipe section surrounded by a helical intermediary pipe section (e.g., heat engine  300 ), the heat engine  400  includes a single substantially linear intermediary pipe section  402  surrounded by helical first and second pipe sections  404 ,  406 . The second pipe section  406  functions as a compression chamber. The intermediary pipe section  402  functions as a working fluid accumulation or pressurization chamber. The first pipe section  404  functions as an expansion chamber that drives the magnetic piston passing through the first pipe section  404  and, each of the three internal, magnetically linked pistons (not shown) by mechanical advantage. Each of the three pistons continuously circulates the internal pathway of the heat engine  400 , sequentially passing through the pipe sections  402 - 406  while maintaining the substantially aligned and magnetically linked connection. Liquid or gas fuel is added at the fuel injector  408 , and an igniter  410  is provided. As combustion occurs, excess kinetic energy can be drawn off by the generator winding coils  412 . The heat engine  400  also includes the air intake induction/exhaust section  414 . 
       FIG.  21    is a perspective view of an exemplary piston  500  (e.g., an electromagnetic piston) capable of being used with the heat engines discussed herein. The piston  500  generally includes a body  502  with two ends  504 ,  506  defined by radial flanges. The ends  504 ,  506  can define diameters dimensioned greater than the cross-sectional diameter of the cylindrical body  502  to ensure the position of windings is maintained on the body  502 . The piston  500  includes a central, separating flange  508  extending from the body  502 . The flange  508  can be positioned closer to the end  506 . The piston  500  includes a large winding  510  (e.g., coil winding) and a small winding  512  (e.g., coil winding) fabricated from a conductive material (e.g., copper, materials suitable for high temperatures, or the like). The small winding  512  can receive an external DC or AC magnetic field, which can induce an electromagnetic field (EMF) into the large winding  510 . The coil windings on the exterior of the heat engine can induce electrical current to the small winding  512 , which results in a generator or alternator, motor effect on the piston  500  via exclusively electromotive force excitation. Therefore, no physical permanent magnet is used with the piston  500 , preventing alteration of operation of the heat engine due to the Curie temperature effect. It should be understood that the piston  500  can be used as the pistons discussed with respect to the heat engines  100 ,  200 ,  300 . 
     While exemplary embodiments have been described herein, it is expressly noted that these embodiments should not be construed as limiting, but rather that additions and modifications to what is expressly described herein also are included within the scope of the invention. Moreover, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations, even if such combinations or permutations are not made express herein, without departing from the spirit and scope of the invention.