Patent Publication Number: US-2016238265-A1

Title: Peak load shifting via thermal energy storage using a thermosyphon

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of PCT Application No. PCT/US2014/062609 filed on Oct. 28, 2014 and entitled “PEAK LOAD SHIFTING VIA THERMAL ENERGY STORAGE USING A THERMOSYPHON”. PCT Application No. PCT/US2014/062609 claims priority to, and the benefit of, U.S. Provisional Application Ser. No. 61/897,029 filed on Oct. 29, 2013 and entitled “PEAK LOAD SHIFTING VIA THERMAL ENERGY STORAGE USING ICE WITH A THERMOSYPHON FOR DISCHARGE.” Both of the above applications are hereby incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to heating and cooling systems, and specifically to heating and cooling systems which use stored thermal energy. 
     BACKGROUND 
     Peak summertime afternoon electrical loads are of great concern to electrical utilities, because summertime peak loads are responsible for large capital generation costs and strain on the power transmission and distribution grids. The peak loads are also of concern to cost-conscious customers, because these afternoon times of day often have per-kW-hour costs several times higher than off-peak costs. Air Conditioning (AC) units, and particularly residential units, are a major source both of the afternoon summertime peak loads on the power grid, and of growth in these loads. Because small AC units are typically the single largest source of power grid peak loads in hot regions, and because they represent a point of union between the financial interests of both power utilities and power customers, it is in the interest of all parties that a cost-effective “peak shaving” system be developed, for example for single family residences, to effectively shift peak loads to the morning and nighttime hours. Ideally, this system would be (i) a “bolt-on” solution that is easily added as a retrofit option without tearing into the structure, (ii) cost-effective, and (iii) scalable to larger residences and commercial operations. Accordingly, improved cooling systems remain desirable. 
     SUMMARY 
     Systems and methods for heating and cooling utilizing stored thermal energy are disclosed. In an exemplary embodiment, a cooling system comprises a compressor, a condenser coil, an evaporator coil, and a thermal energy storage unit. The cooling system further comprises a first 3-way valve positioned between the condenser coil and the evaporator coil, and a second 3-way valve positioned between the evaporator coil and the compressor. The thermal energy storage unit and the evaporator coil form a thermosyphon. 
     In another exemplary embodiment, a method of providing cooling comprises operating a cooling system in an energy consumption mode, operating the cooling system in an energy storage mode, and operating the cooling system in an energy discharge mode. 
     In another exemplary embodiment, a thermal energy storage system comprises a thermal energy storage unit, a first 3-way valve configured to be inserted between a condenser coil and an evaporator coil in an existing cooling system, and a second 3-way valve configured to be inserted between the evaporator coil and a compressor in the existing cooling system. The thermal energy storage unit is configured to form a thermosyphon with the evaporator coil. 
     The foregoing summary is provided as a simplified introduction to the disclosure, and is not intended to be used to limit the scope of the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       With reference to the following description and accompanying drawings: 
         FIG. 1  illustrates an exemplary cooling system in an energy consumption mode according to various embodiments; 
         FIG. 2  illustrates an exemplary cooling system in an energy storage mode according to various embodiments; 
         FIG. 3  illustrates an exemplary cooling system in an energy discharge mode according to various embodiments; 
         FIG. 4  illustrates an exemplary thermal energy storage unit according to various embodiments; 
         FIG. 5  illustrates a top view of an exemplary thermal energy storage unit according to various embodiments; 
         FIG. 6  illustrates an exemplary thermal energy storage system having a primary tank and two secondary tanks according to various embodiments; 
         FIG. 7  illustrates a block diagram of an exemplary rotary valve apparatus according to various embodiments; 
         FIG. 8  illustrates a side view of an exemplary rotary valve apparatus according to various embodiments; and 
         FIGS. 9-11  illustrate section views of an exemplary rotary valve apparatus according to various embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is of various exemplary embodiments only, and is not intended to limit the scope, applicability or configuration of the present disclosure in any way. Rather, the following description is intended to provide a convenient illustration for implementing various embodiments including the best mode. As will become apparent, various changes may be made in the function and arrangement of the elements described in these embodiments without departing from the scope of the present disclosure. 
     In accordance with principles of the present disclosure, thermal energy systems may store energy for use at a later time. For example, ice may be generated in a thermal energy storage unit, and the ice may later be used to cool a refrigerant which provides cooling, for example to a residential air-conditioning system. The ice may be formed during periods of low energy demand, and the stored thermal energy may be discharged during periods of high energy demand. One or more valves, for example 3-way valves, may direct refrigerant through a compressor to store energy or provide cooling during periods of low energy demand, and the valves may be switched to direct refrigerant from the thermal energy storage unit to an evaporator coil during periods of high energy demand to provide cooling, for example to a residence. 
     In various exemplary embodiments, a thermal energy storage unit may be coupled to the evaporator coil in a thermosyphon. As refrigerant cools in the thermal energy storage unit, the refrigerant may become more dense, and gravity may pull the denser refrigerant downward through the thermal energy storage unit. The refrigerant may flow to the evaporator coil. As the refrigerant warms or evaporates in the evaporator coil, the refrigerant may become less dense, and the less dense refrigerant may flow upwards and back to the thermal energy storage unit. Thus, the refrigerant may flow between the thermal energy storage unit and the evaporator coil without use of a pump. A fan may direct air through the evaporator coil to provide cooled air to the residence. 
     Referring now to  FIG. 1 , a cooling system  100  is illustrated in energy consumption mode according to various embodiments. Cooling system  100  may comprise a compressor  110 , a condenser coil  120 , an evaporator coil  130 , and a thermal energy storage unit (“TES”)  140 . During energy consumption mode, compressor  110  may compress a gas refrigerant in cooling system  100 . The refrigerant may flow through condenser coil  120  and condense into a liquid. A condenser fan  125  may blow air through condenser coil  120  to partially cool the refrigerant. As the refrigerant condenses in condenser coil  120 , a temperature of the refrigerant may decrease. A first 3-way valve  150  positioned between condenser coil  120  and evaporator coil  130  may direct the refrigerant to evaporator coil  130 . The condensed and pressurized liquid refrigerant is next routed through an expansion valve  160  where it undergoes an abrupt reduction in pressure. The pressure reduction results in flash evaporation of a portion of the liquid refrigerant, lowering its temperature. The cold refrigerant is then routed through evaporator coil  130 . The refrigerant may flow through evaporator coil  130  and evaporate into a gas. An evaporator fan  135  may blow air through evaporator coil  130  to provide chilled air to a residence. A second 3-way valve  155  positioned between evaporator coil  130  and compressor  110  may direct the refrigerant back to compressor  110 . 
     In various embodiments, in cooling system  100  the direction of flow of the refrigerant may be reversed, for example in order to provide heating to a residence. In such cases, a second 3-way valve  155  directs refrigerant from compressor  110  to evaporator coil  130 , and first 3-way valve  150  directs refrigerant from evaporator coil  130  through condenser coil  120  and to compressor  110 . During heating, condenser coil  120  may act as an evaporator coil, and evaporator coil  130  may act as a condenser coil. 
     Referring now to  FIG. 2 , cooling system  100  is illustrated in energy storage mode according to various embodiments. During operating of cooling system  100  in an energy storage mode, first 3-way valve  150  may direct the refrigerant from condenser coil  120  to TES  140 . The condensed and pressurized liquid refrigerant is routed through an expansion valve  165  where it undergoes an abrupt reduction in pressure. The pressure reduction results in flash evaporation of a portion of the liquid refrigerant, lowering its temperature. A check valve  171  in a vapor return line  170  may prevent refrigerant from flowing into evaporator coil  130  through vapor return line  170 . The cooled refrigerant may flow through a cooling coil  142  in TES  140 . Cooling coil  142  may chill an energy storage medium located within TES  140 . For example, the energy storage medium may comprise water, a brine solution, or other suitable energy storage medium. As the refrigerant flows through cooling coil  142 , heat may be transferred from the energy storage medium to the refrigerant via cooling coil  142 . As heat is transferred from the energy storage medium to the refrigerant, the temperature of the energy storage medium may decrease. In various embodiments, the energy storage medium may freeze within TES  140 . This heat transfer may cause the temperature of the refrigerant in cooling coil  142  to increase. The refrigerant may exit TES  140  via a TES return line  145 . TES return line  145  may return the refrigerant to second 3-way valve  155 . Second 3-way valve  155  may direct the refrigerant back to compressor  110 . The refrigerant may continue to flow in a loop from compressor  110 , through condenser coil  120 , through TES  140 , and back to compressor  110 , in order to chill the energy storage medium and thus store thermal energy in TES  140 . 
     Referring now to  FIG. 3 , cooling system  100  is illustrated in an energy discharge mode according to various embodiments. In an energy discharge mode, second 3-way valve  155  directs refrigerant in TES return line  145  from TES  140  to evaporator coil  130 , bypassing compressor  110  and condenser coil  120 . In various embodiments, first 3-way valve  150  may direct refrigerant from evaporator coil  130  to TES  140 . However, in various embodiments, all (or a majority of) the refrigerant exiting evaporator coil  130  may flow through a vapor line  170  to TES  140 . Thus, compressor  110  and condenser coil  120  may not be used during an energy discharge mode. The cooled refrigerant from TES  140  evaporates in evaporator coil  130 . Evaporator fan  135  may blow air through evaporator coil  130 , for example to provide chilled air to a residence. The gas refrigerant may return to TES  140  via vapor line  170  and through check valves  172 ,  171 . The refrigerant may flow through cooling coil  142 , and the energy storage medium in TES  140  may cool the refrigerant. The cooled refrigerant may be returned to evaporator coil  130  for additional cooling of the residence. The refrigerant may continue to flow through the loop between TES  140  and evaporator coil  130 , for example until the energy stored in TES  140  is fully discharged, or until no additional cooling is desired. 
     In various embodiments, TES return line  145  may exit TES  140  at a location with higher gravitational potential energy than a location of evaporator coil  130 . Thus, the refrigerant in TES return line  145  may flow to evaporator coil  130  without use of an additional pump. The less dense refrigerant exiting evaporator coil  130  may also return to TES  140  without use of a pump. Thus, TES  140  and evaporator coil  130  may together form a thermosyphon, in which refrigerant is transferred between TES  140  and evaporator coil  130  without use of a pump. 
     In accordance with principles of the present disclosure, a thermosyphon configuration may allow circulation of refrigerant without the necessity of a mechanical pump. As the refrigerant is heated and evaporates, the refrigerant becomes less dense, and thus more buoyant than the cooler refrigerant. Convection moves the less dense refrigerant upwards in the system as it is replaced by cooler refrigerant returning from TES  140  by gravitational force. Thus, in an energy discharge mode, evaporator fan  135  may be the only component of cooling system  100  which utilizes electricity. This may result in decreased energy consumption during the energy discharge mode, for example in comparison to systems which use a pump to circulate refrigerant. 
     In various exemplary embodiments, the amount of cooling provided to a residence during energy discharge mode operation of cooling system  100  may be controlled by controlling operation of evaporator fan  135 . Increasing power to evaporator fan  135  may increase the rate of evaporation of the refrigerant and thus increase the rate of circulation of the refrigerant. However, in various embodiments, a throttle valve may be inserted in vapor line  170  or TES return line  145  in order to control the rate of circulation of refrigerant. Moreover, any suitable control scheme or components to direct operation of evaporator fan  135  may be utilized, as desired. 
     In various embodiments, TES  140  may be retrofitted and/or retrofittable into an existing cooling system. An existing cooling system may comprise a compressor  110 , a condenser coil  120 , and an evaporator coil  130 . In order to retrofit the existing cooling system, a first 3-way valve  150  may be installed, for example between condenser coil  120  and evaporator coil  130 . A second 3-way valve  155  may be installed, for example between evaporator coil  130  and compressor  110 . TES  140  may be connected to the first 3-way valve  150  and the second 3-way valve  155 , and vapor line  170  may connect TES  140  to evaporator coil  130 . Thus, in accordance with principles of the present disclosure, existing cooling systems may be retrofitted with only minor modifications in order to integrate with exemplary thermal energy storage systems and use a thermosyphon to cycle refrigerant. 
     Referring now to  FIG. 4 , TES  140  is illustrated according to various embodiments. TES  140  may comprise a tank  410 . Tank  410  may comprise any type of receptacle capable of containing a liquid. For example, in various embodiments, tank  410  may comprise a cylindrical barrel, a rectangular box, or any other suitable receptacle. In various embodiments, tank  410  may be insulated, such as with multi-panel walls, or with an exterior insulation  440  coupled to tank  410 . 
     A cooling coil  142  may be located within tank  410 . In various embodiments, cooling coil  142  may be formed from copper refrigerant tubing. The cooling coil  142  may be configured with a constant downward slope, such that no traps form which may deprive the compressor of oil. In various embodiments, cooling coil  142  may comprise a single helical coil extending from top  412  of tank  410  to bottom  414  of tank  410 . However, cooling coil  142  may comprise a variety of shapes, including a spiral coil as described with reference to  FIG. 5 . The shape of cooling coil  142  may be selected such that ice forms generally in a center of tank  410  while leaving a liquid layer at the walls of tank  410 , for example in order to avoid outward pressure on the tank walls which may damage tank  410 . 
     A plurality of fins  420  may be coupled to cooling coil  142 . The fins  420  may comprise a piece of copper sheet or other suitable thermally conductive material. Fins  420  may provide additional surface area which may aid in heat transfer between cooling coil  142  and the thermal storage medium within tank  410 . 
     In various embodiments, TES  140  may comprise an internal frame  430  to provide structural integrity and/or support to TES  140  and/or components therein. Internal frame  430  may be preloaded against top  412  of tank  410 . Moreover, cooling coil  142  may be coupled to internal frame  430 . Cooling coil  142  may be subjected to a buoyancy force from the thermal storage medium. However, coupling cooling coil  142  to internal frame  430  may prevent movement of cooling coil  142  within tank  410 . 
     Referring now to  FIG. 5 , TES  500  is illustrated according to various embodiments. In TES  500 , a cooling coil  542  may be configured as a spiral coil. To form cooling coil  542 , a copper refrigerant tubing may be formed around a tool designed to provide coil loops of decreasing diameters. For example, a first coil loop  543  may be configured with roughly a 16 inch diameter, a second coil loop  544  may be configured with roughly a 10 inch diameter, and a third coil loop  545  may be configured with roughly a 4 inch diameter. However, in various embodiments, any suitable diameters or rates of coil diameter reduction may be used for the coil loops. Additionally, a plurality of spiral coils may be coupled together and distributed within TES  500 . The spiral coils may be coupled to internal frame  530  in order to prevent displacement of the cooling coils. 
     Referring now to  FIG. 6 , in various exemplary embodiments a TES  600  is configured with at least one secondary storage tank, for example two secondary storage tanks  620 . TES  600  may comprise a primary tank  610  and one or more secondary storage tanks  620 . A pump, for example brine pump  630 , may pump the energy storage medium from primary tank  610  through secondary storage tanks  620  and back to primary tank  610 . Secondary storage tanks  620  may provide additional storage capability to TES  600 . Brine pump  630  may circulate the energy storage medium during charging of TES  600 , storing additional thermal energy in secondary storage tanks  620 . During discharge of TES  600 , brine pump  630  may circulate the energy storage medium through secondary storage tanks  620  and primary tank  610  to provide additional stored thermal energy to TES  600 , which may be used to cool the refrigerant flowing through cooling coil  642  in primary tank  610 . 
     Referring now to  FIGS. 1 and 7 , in various embodiments, the first 3-way valve  150  may comprise a rotary valve apparatus  700 , and second 3-way valve  155  may comprise a rotary valve apparatus  700 . The first 3-way valve  150  and the second 3-way valve  155  may be configured to be similarly sized, similarly constructed, and or similarly operational; moreover, the first 3-way valve  150  and the second 3-way valve  155  may differ from one another, for example in size, materials, and/or the like, in order to achieve one or more desired operational characteristics of the cooling system  100 . 
     In various embodiments, a rotary valve apparatus  700  comprises a case  702 , a fluid conducting apparatus  704 , an electromechanical actuator  706 , and a plurality of fluid ports  708 . In various embodiments, a rotary valve apparatus  700  further comprises a balance port  812  (as illustrated in  FIG. 9 ) and a solenoid coil  1010  (as illustrated in  FIG. 8 ), as further discussed herein below. 
     Referring to  FIGS. 7-9 , case  702  may comprise a plurality of fluid ports  708 , for example disposed circumferentially about the perimeter of the case  702 . In one example embodiment, three ports are arranged about the case  702 . In one example embodiment, these ports are disposed at about 120 degrees from each other, though any position suitably configured to interface with refrigerant lines may be utilized. In one example embodiment, the ports are configured as ¼″ NPT, and the portion of the body about which the ports are disposed has a diameter of about 1.700″, though any dimension configured to permit the fluid ports  708  to connect in fluid communication with the fluid conducting apparatus  704  may be adopted. 
     Furthermore, rotary valve apparatus  700  may be a two position valve, or a four position valve, or a valve having any number of positions adaptably configured to interconnect any number of components with a fluid system. As such, in accordance with principles of the present disclosure, a rotary valve apparatus  700  may have two ports, or four ports, or may have any number of ports arranged about the case in any pattern adapted to interconnect components with a fluid system. 
     In one example embodiment, case  702  is hermetically sealed. Case  702  may comprise  700  series stainless steel and be welded together to make a hermetically sealed unit. In another example embodiment, 2″ diameter 6061-T6 bar stock may be chosen for case  702 , though any metal, ceramic, alloy, composite, or other material suitable for forming case  702  may be utilized. In one example embodiment, a pair of SAE #220 Nitrile rubber O-rings may be utilized to seal portions of a case  702 , though any O-ring or other sealing mechanism or component that results in an acceptable seal may be utilized. In one example embodiment, case  702  has an inner diameter of about 1.625″, though any diameter suitable for use in conjunction with a chosen O-ring and acceptable case fatigue life may be utilized. Still further, one example embodiment may also comprise an internal snap ring, for example having a size of between about 1.5″ and about 2″, and preferably about 1.75″. It will be appreciated that the foregoing dimensions and configuration for case  702  are given by way of example, and not of limitation. 
     Referring now to  FIGS. 8 and 9 , case  702  may be configured with a cylindrical housing. In various embodiments, case  702  may further comprise a conic section. However, case  702  may comprise any shape, geometry, or structure of housing configured to retain a fluid conducting apparatus  704 . In various embodiments, case  702  further comprises three fluid ports  708 , and a first locking surface  802 . First locking surface  802  may comprise an internal face of case  702  configured to interface with fluid conducting apparatus  704  (for example, a second locking surface  808  of fluid conducting apparatus  704 ). 
     In various embodiments, fluid conducting apparatus  704  is disposed within case  702 . Fluid conducting apparatus  704  may be movable in response to operation of electromechanical actuator  706 . In various embodiments, fluid conducting apparatus  704  is axially rotatable about an axis  710  passing through the center of case  702 . Fluid conducting apparatus  704  may be moved in response to operation of electromechanical actuator  706  and may connect various fluid ports  708 , for example in pairs. 
     In various embodiments, fluid conducting apparatus  704  comprises a second locking surface and a first transfer passage. For example, fluid conducting apparatus  704  may comprise second locking surface  808 . Second locking surface  808  may comprise a surface of fluid conducting apparatus  704  configured to interface with first locking surface  802  of case  702 . In this manner, first locking surface  802  may comprise a face of a conic portion of case  702 , and second locking surface  808  may comprise a face of a conic portion of fluid conducting apparatus  704 . In various embodiments, first locking surface  802  and second locking surface  808  may comprise a face of a differently shaped portion of a case  702  and fluid conducting apparatus  704 , respectively. Moreover, first locking surface  802  and second locking surface  808  may comprise faces having any shapes, coatings, roughness, or texturing suitable for holding the fluid conducting apparatus  704  in substantially fixed rotational position, for example, to prevent the fluid conducting apparatus  704  from inadvertent movement or rotation, while still also permitting desired movement or rotation. 
     In various embodiments, fluid conducting apparatus  704  comprises a first transfer passage  810 . First transfer passage  810  may comprise a hollow aperture substantially aligned with a chord of fluid conducting apparatus  704 . However, first transfer passage  810  may comprise any aperture, pathway, tunnel, tube, or conduit having any orientation such that first transfer passage  810  may be oriented to connect two fluid ports  708 . 
     With reference now to  FIGS. 7-11 , in various embodiments, rotary valve apparatus  700  comprises an electromechanical actuator  706 . An electromechanical actuator  706  may comprise a reluctance actuator  804  and a magnetic rotor  806 . In various embodiments, reluctance actuator  804  may generate an electromagnetic field whereby a motive force may be exerted on magnetic rotor  806 . For example, in various embodiments a reluctance actuator  804  may comprise at least one coil of wire which generates an electromagnetic field when energized. In various embodiments, magnetic rotor  806  comprises a semicircular body comprising a ferromagnetic material. However, any suitable shape for magnetic rotor  806  may be utilized. In various embodiments, magnetic rotor  806  is attached to fluid conducting apparatus  704 . Thus, reluctance actuator  804  may exert a motive force on magnetic rotor  806  whereby fluid conducting apparatus  704  may be translated along axis  710  and/or rotated about axis  710 . In this manner, fluid conducting apparatus  704  may be selectively moved so that the fluid transfer passage  810  selectively connects different fluid ports  708 . 
     In various embodiments, a reluctance actuator  804  comprises a first coil pair  1001 , a second coil pair  1003 , and a third coil pair  1007 . Each coil pair may be positioned at least partially around the circumference of case  702 , such that each coil pair, when energized, impels fluid conducting apparatus  704  to be selectively moved to connect a different pair of fluid ports  708 , in accordance with the principles disclosed herein. 
     Moreover, in various embodiments, each coil pair comprises a clockwise stator coil and a counterclockwise stator coil. For example, first coil pair  1001  may comprise a clockwise stator coil  1002  and a counterclockwise stator coil  1004 . Second coil pair  1003  may comprise a clockwise stator coil  1005  and a counterclockwise stator coil  1006 . Third coil pair  1007  may comprise a clockwise stator coil  1008  and a counterclockwise stator coil  1009 . A clockwise stator coil may comprise a wound coil of wire having the wire wound in an opposite direction compared to a counterclockwise stator coil. In this manner, and in accordance with the right-hand rule, a clockwise stator coil and the corresponding counterclockwise stator coil may generate magnetic lines of force operating in opposite directions. Thus, a north magnetic pole and a south magnetic pole may be established for each coil pair. In various embodiments, by selectively energizing different coil pairs, magnetic rotor  806  may be moved to different orientations coinciding with the different coil pairs. In various example embodiments, coils of 250 turns of 28 gauge magnet wire potted in epoxy may be used. Moreover, any suitable number of turns and any suitable gauge of wire may be utilized in order to ensure reliable operation of reluctance actuator  804 . 
     In one example embodiment, the windings alternate between clockwise (CW) and counter-clockwise (CCW) windings so that each position has a north magnetic pole, and a south magnetic pole, though any winding configuration adapted to cause the valve to rotate when actuated may be implemented. In one example embodiment, reluctance actuator  804  comprises three pairs of windings, though any number of windings or pairs of windings may be utilized to permit the valve to interface with a particular number and arrangement of ports. 
     Furthermore, in one example embodiment, the windings are wired in a Y configuration, with the common leg going through an optional coil to produce rotor thrust. Thus, a rotary valve apparatus  700  may comprise a solenoid coil  1010 . Solenoid coil  1010  may be configured to help lift fluid conducting apparatus  704  to disengage second locking surface  808  from first locking surface  802 , for example in order to reduce the torque needed to move and/or rotate fluid conducting apparatus  704 . In other example embodiments, solenoid coil  1010  may be omitted. For example, solenoid coil  1010  may be omitted if the coil pairs are installed with a sufficiently high elevation so as to lift the fluid conducting apparatus  704  without a solenoid coil  1010 . 
     In various embodiments, reluctance actuator  804  further comprises a lamination stack  814 . In one example embodiment, the lamination stack  814  may comprise 26 layers of a six pole laminate of 0.018″ thick M-19 electrical steel. However, any suitable lamination architecture configured to operate the rotary valve apparatus  700  at a desired operational voltage and current and with desired operational characteristics may be implemented. In various embodiments of rotary valve apparatus  700 , the coils fit into slots of the lamination stack  814  of reluctance actuator  804 . In one embodiment, the laminate design has about a 1.700″ diameter bore with the pole width generally equal to the space in between poles. It will be appreciated that the foregoing dimensions and sizes are given by way of example and illustration, and not of limitation. 
     Referring now to  FIGS. 8, 10, and 11 , in various embodiments, a magnetic rotor  806  may comprise a semicircular body comprising a ferromagnetic material. In various embodiments, magnetic rotor  806  is attached to fluid conducting apparatus  704 . Thus, when magnetic rotor  806  is translated or rotated in response to selectively energizing different coil pairs of reluctance actuator  804 , fluid conducting apparatus  704  is similarly translated and/or rotated. The semicircular body of magnetic rotor  806  may have an arc length of sufficient length relative to (i) the circumference of case  702  and (ii) the positioning of the stator coil pairs, such that by energizing an adjacent coil pair, the magnetic rotor  806  may be moved from an orientation corresponding with one coil pair, to an orientation corresponding with the adjacent coil pair. For example, magnetic rotor  806  may be positioned corresponding with first coil pair  1001 . In various embodiments, by energizing the third coil pair  1007 , magnetic rotor  806  may be influenced to reorient corresponding with the third coil pair  1007 . Alternatively, by energizing the second coil pair  1003 , magnetic rotor  806  may be influenced to move to a position corresponding with the second coil pair  1003 . In this manner, a magnetic rotor  806  oriented corresponding to any stator coil pair may be influenced to move to a position corresponding with another stator coil pair by energizing the stator coil pair corresponding to the desired position. 
     In various embodiments, magnetic rotor  806  comprises a plurality of semicircular sections. For example, referring again to  FIG. 11 , in various embodiments, magnetic rotor  806  comprises a magnetically influenced section  1104  and a counterweight section  1102 . In this manner, the balance of the magnetic rotor  806  may be improved. In various embodiments, magnetically influenced section  1104  comprises a highly ferromagnetic material, for example iron, steel, and/or the like. In various embodiments, counterweight section  1102  comprises a material less ferromagnetic than magnetically influenced section  1104 , for example copper, brass, and/or the like. 
     In various embodiments, magnetically influenced section  1104  and counterweight section  1102  are configured with different sizes. For example, counterweight section  1102  may be sized so as to be less able to be stably oriented by reluctance actuator  804 , whereas magnetically influenced section  1104  may be sized so as to acquiesce to a stable orientation when influenced by reluctance actuator  804 . In this manner, the magnetic rotor  806  may have a single stable orientation corresponding to each stator coil pair. 
     In various embodiments, rotary valve apparatus  700  utilizes external power only during movement from a first (i.e., original) position to a second (i.e., new) position. With reference to  FIG. 10 , in one example embodiment, magnetic rotor  806  is configured with a notch  816 . Notch  816  may be disposed in the center along the arc length of the magnetic rotor  806 . Moreover, notch  816  may be located in any suitable location such that magnetic rotor  806  is configured to increase the restoring torque versus misalignment curve slope. Moreover, magnetic rotor  806  may be sized, shaped, and/or configured with any suitable components or arrangements such that magnetic rotor  806  is configured to increase the restoring torque versus misalignment curve slope. In one example embodiment, notch  816  is off-center so that magnetic rotor  806  is sufficiently proximate to adjacent coil pairs to provide initial torque and lift to start movement of magnetic rotor  806  to a new position. 
     In certain embodiments, magnetic rotor  806  may comprise a polyimide plastic and have two sections of about 120 degrees. Referring to  FIG. 11 , in various embodiments, these sections comprise a magnetically influenced section  1104  and a counterweight section  1102 . For example, counterweight section  1102  may be made of copper and magnetically influenced section  1104  may be made of mild steel, though any configuration adapted to permit magnetic rotor  806  to function may be utilized. Furthermore, the height of the steel sector may be about 0.5″, and the height of the copper sector may be reduced below the height of the steel sector, for example, to make the copper sector weigh about the same as the steel sector. Moreover, it will be appreciated that any configuration yielding appropriate balance may be implemented. 
     In one example embodiment, the sectors of magnetic rotor  806  are not both 120 degree sections, but differ from one another, for example in arc length, height, thickness, material, and/or the like. In one example embodiment, the magnetic rotor copper sector may be drilled and countersunk to accept a fastener, for example a 1.5″ long brass 8-32 flat head screw, and the steel sector may be drilled and tapped with an 8-32 thread. An 8-32 screw may then be implemented to join the magnetic rotor sectors. However, any suitable method or components for coupling portions of magnetic rotor  806  may be utilized, as desired. 
     Referring now to  FIG. 9 , in various embodiments, rotary valve apparatus  700  further comprises a balance port  812 . For example, balance port  812  may be configured as an aperture through case  702  through which tools may be inserted to remove (e.g., drill out) material from fluid conducting apparatus  704  and/or magnetic rotor  806 . In this manner, the balance of the various components of the rotary valve apparatus  700  may be fine-tuned, as desired. 
     Referring back to  FIG. 8 , in various embodiments, rotary valve apparatus  700  further comprises a solenoid coil  1010 . For example, in some embodiments, reluctance actuator  804  is oriented so as to exert insufficient lift force to disengage second locking surface  808  from first locking surface  802 . Thus, in some embodiments, solenoid coil  1010  is implemented to provide lift force to disengage the locking surfaces prior to rotation of the magnetic rotor  806  to correspond to a stator coil pair of the reluctance actuator  804 . 
     In various embodiments, case  702  further comprises an axis shaft  712 . Axis shaft  712  lies coincident with axis  710 . In various embodiments, fluid conducting apparatus  704  is supported by axis shaft  712  and rotates axially about axis shaft  712 . In various embodiments, axis shaft  712  connects to fluid conducting apparatus  704  and magnetic rotor  806 . As a result, axis shaft  712  may rotate and translate in unison with fluid conducting apparatus  704  and magnetic rotor  806 . Axis shaft  712  may be supported at one end, for example by a spring assembly  714 . Spring assembly  714  is configured to impel axis shaft  712 , and correspondingly fluid conducting apparatus  704 , toward the first locking surface  802  of case  702 . Thus, spring assembly  714  may exert a seating force, seating second locking surface  808  against first locking surface  802 . In various embodiments, solenoid coil  1010  may be positioned to exert a force on magnetic rotor  806  in a direction opposite of spring assembly  714 . In this manner, solenoid coil  1010  may assist the disengagement and/or engagement of second locking surface  808  with first locking surface  802 . 
     Axis shaft  712  may comprise any suitable material configured to permit the rotary valve apparatus  700  to actuate, for example music wire having a diameter of between about 0.8 mm and about 1.2 mm. In one embodiment, jewel bearings support certain moving components of a rotary valve apparatus  700 . The jewel bearings may comprise hematite cylindrical beads and/or the like, although any bushing, bearing, or material chosen for acceptable frictional characteristics may be used. 
     Furthermore, axis shaft  712  may optionally be omitted, or alternatively, may be used to increase the axial forces during actuation and/or to increase the axial forces at rest, and/or to reduce the drag torque during actuation, and/or to increase the holding torque during rest. Axis shaft  712  and/or magnetic rotor  806  may be configured, responsive to operation of solenoid coil  1010 , to produce a high initial lift force to free fluid conducting apparatus  704  from case  702 . 
     In accordance with the principles of the present disclosure, rotary valve apparatus  700  may be positioned so that axis  710  is vertical and reluctance actuator  804  is positioned above magnetic rotor  806 . Thus, at rest, second locking surface  808  of fluid conducting apparatus  704  rests on first locking surface  802  of case  702 . When a pair of coils is powered, fluid conducting apparatus  704  is lifted free of first locking surface  802  and pivots to align with the powered coil pair. When power is removed, fluid conducting apparatus  704  may drop onto first locking surface  802  of case  702  and may be held in place by gravity, for example, on first locking surface  802 . Thus, for example, in one embodiment, rotary valve apparatus  700  may only require a small amount of power to change position, and no power during use. 
     In accordance with the principles of the present disclosure, when a pair of coils is powered, magnetic rotor  806  may move, for example, in a 120 degree increment, or any other increment selected to position fluid transfer passage  810  of fluid conducting apparatus  704  to connect at least two fluid ports  708 . In one example embodiment, the coils may be powered by a 12V DC 1 Amp class II transformer with a 0.065 Farad capacitor, though any suitable voltage and/or current source may be utilized. The capacitor may be selected with consideration for the frequency of actuation and actuation force, so the actuator has the greatest magnetic force at just the moment it needs to be operable to lift and pull in the steel sector from an adjacent position. 
     While the principles of this disclosure have been shown in various embodiments, many modifications of structure, arrangements, proportions, the elements, materials and components, used in practice, which are particularly adapted for a specific environment and operating requirements may be used without departing from the principles and scope of this disclosure. These and other changes or modifications are intended to be included within the scope of the present disclosure and may be expressed in the following claims. 
     The present disclosure has been described with reference to various embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present disclosure. Accordingly, the specification is to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present disclosure. Likewise, benefits, other advantages, and solutions to problems have been described above with regard to various embodiments. However, benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or element of any or all the claims. 
     As used herein, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Also, as used herein, the terms “coupled”, “coupling” or any other variation thereof, are intended to cover a physical connection, an electrical connection, a magnetic connection, an optical connection, a communicative connection, a functional connection, and/or any other connection. When language similar to “at least one of A, B, or C” or “at least one of A, B, and C” is used in the claims, the phrase is intended to mean any of the following: (1) at least one of A; (2) at least one of B; (3) at least one of C; (4) at least one of A and at least one of B; (5) at least one of B and at least one of C; (6) at least one of A and at least one of C; or (7) at least one of A, at least one of B, and at least one of C.