Patent Publication Number: US-2023160403-A1

Title: Deployable energy supply and management system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/993,170, filed Mar. 23, 2020, the disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates, in general, to hydraulic energy storage and management systems. In particular, this invention relates to a hydraulic energy management system that has a reconfigurable energy storage and release capability that adjusts to varying available energy input and power demand output requirements. The hydraulic energy management system can be resized by a hydraulic bridge circuit to permit power units to be added or removed, both physically and operationally, to capture available energy over time, adjust to peak demand cycles, and maintain power output in the event of a failure of a portion of the system. 
     Hydraulic management and storage systems utilize accumulators to store hydraulic fluid under pressure and release the stored pressure energy as a mechanical output to drive a device. These systems typically capture energy that would be wasted in the form of heat, such as vehicle braking energy, and re-release the energy when a demand is signaled. The accumulator storage systems are sized to capture a predetermined amount of energy and provide a controlled release of the stored energy through valves regulating fluid flow into a hydraulic motor. In stationary power generation applications capturing wind energy for conversion to electrical energy, the load demand and the input power are variable and unassociated with each other. If part of the circuit fails or the accumulator becomes unable to accept additional energy, the system shuts down. In addition, there is no ability to vary the system capacity by rerouting storage and output capability. Thus, it would be desirable to have a hydraulic energy storage and management system that could be resized to accommodate variations in input and output energy volumes or system failures, particularly in remote environments. 
     SUMMARY OF THE INVENTION 
     This invention relates, in general, to hydraulic energy storage and management systems. In particular, this invention relates to a hydraulic energy management system that has a reconfigurable energy storage and release capability that adjusts to varying available energy input and power demand output requirements. The hydraulic energy management system can be resized by a hydraulic bridge circuit to permit hydraulic power units to be added or removed, both physically and operationally, to capture available energy over time, adjust to peak demand cycles, and maintain power output in the event of a failure of a portion of the system. 
     The hydraulic energy storage and management system can be applied to stationary power applications, particularly remotely located electric generation stations. In one aspect of the invention, the hydraulic energy storage and management system accumulates energy from a wind power source which is stored as pressurized fluid. The system also provides pressurized fluid generated by the external energy source, such as the wind power source, directly to the output load, such as an electric generator. When energy supply is in excess of power demand, the pressurized fluid may be stored in a series of fluid accumulators. These accumulators, and the supporting hydraulic circuitry, are arranged in cells that may be connected together, in series or in parallel, to form energy management pods. In one aspect of the invention, electrical energy is produced from a release of the stored pressurized fluid in each cell as the demand requires. The fluid pressure is released from the accumulators based on the demand and the available incoming power. 
       FIG.  1    is the basic hydraulic circuit used to store the wind-generated hydraulic pressure and release it, based on a load demand.  FIGS.  2 A -  2 C  are the basic cell unit having a plurality of the fluid circuits of  FIG.  1    and  FIG.  3    is the portable “pod” having a plurality of cells that are “plug-and-play.” As will be described below, in the event of a cell failure or in order to balance the system output with the load demand and input power supply (i.e., windy vs. calm conditions), cells or portions of cells can be brought on-line and balanced with the system demand and available input energy to maintain a desired power output. 
     Peak load management system: An energy management system that consumes power during times of low energy cost and supplements or replaces power needs. The energy is stored by mechanical means. This embodiment uses a device that has a barrier between a compressible material (gas) and a non-comprisable material (Liquid) to store energy. The system charges by power from the supply source when energy is abundant or at lower cost. 
     Energy balancing system: Despite mechanical energy storage systems for mechanical energy storage systems being capable of being interconnected with different states of charge if they cannot be isolated from each other, charged and discharged independently or in banks it become difficult if not impossible to tell if a single mechanical unit has failed in the system. This system allows for the isolation of charging and discharging of both modes in banks or single units to locate equipment needing service without bringing whole system out of operation. Energy storage systems of all types have characteristics that change over time and even fail eventually due to time and use or due to defects in their fabrication. When these systems or devices are small in size or reliability of the system is not critical, simple maintenance schedules may be created to reduce the likelihood of failure. These failures range from loss of performance to a component or sub-system ‘weak link’ failure which may cause rapid oxidation (over heating or fire) or a loss of compressible gas or fluid (leak or burst). 
     This invention provides a mechanical energy storage device configured as an accumulator or as an accumulator and connected gas spring storage means that may be controlled for partition and selective activation or deactivation by way of a hydraulic circuit element. In one embodiment, the accumulator has a compressible fluid (gas) on one side of a barrier and an incompressible fluid (Fluid) on the other side of the barrier. As the fluid is moved in and out of the accumulator, energy is stored through compression of the gas and released during expansion of the gas. The hydraulic circuit element is an actuatable series of valves, some arranged in a Wheatstone Bridge configuration and others provided in conjunction with accumulator fluid or gas volumes, to permit pressurized fluid to be directed to generate power, redirect compressible gas volumes to other accumulator arrangements, and/or isolate accumulators based on a state of charge/discharge or operational capacity. 
     Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic of a hydraulic circuit for use in a power cell of a power pod system in accordance with the invention. 
         FIG.  2 A  is a perspective view of a hydraulic power cell having 1 or more hydraulic circuits of  FIG.  1   . 
         FIG.  2 B  is an elevational view of an embodiment of an accumulator and separate charge tank, applicable to the hydraulic circuit of  FIG.  2 A . 
         FIG.  2 C  is an elevational view of another embodiment of an accumulator and separate charge tank, applicable to the hydraulic circuit of  FIG.  2 A . 
         FIG.  3    is an exploded, perspective view showing a plurality of power cells of  FIG.  2    forming a hydraulic power pod in accordance with the invention. 
         FIG.  4 A  is a perspective view of an alternate embodiment of the manifold illustrated in  FIG.  3   , showing the configured as a modular manifold system. 
         FIG.  4 B  a perspective view of an alternative embodiment of the manifold illustrated in  FIG.  4 A  configured as a plurality of pipes. 
         FIG.  5    is an alternate embodiment of the hydraulic circuit illustrated in  FIG.  1    showing the Wheatstone Bridge circuit applied to the gas side of the accumulator. 
         FIG.  6    is a perspective view of the accumulator and separate charge tank illustrated in  FIG.  2 B  shown connected to the hydraulic circuit and having the isolation valve on the gas charge side. 
         FIG.  7    is a perspective view of a plurality of the accumulators and separate charge tanks illustrated in  FIG.  2 B  shown connected to the hydraulic circuit and having the isolation valve on the gas charge side. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, there is illustrated in  FIG.  1    a schematic of a hydraulic circuit, shown generally at  10 , that forms a basic control circuit for the hydraulic cells, discussed below. The hydraulic circuit  10  includes a hydraulic-based Wheatstone bridge, shown generally at  12 , and comprising solenoid actuated valves  14   a ,  14   b ,  14   c , and  14   d . The valves may be any type of hydraulic flow control valve, such as check valves, spool valves, ball valves, and the like. In the illustrated embodiment, the valves  14   a - 14   d  are one-way check valves. Each of the valves  14   a - 14   d  may be actuated to permit flow bi-directionally by activating the solenoid portion of the valves. 
     Energy, in the form of pumped hydraulic fluid, enters the circuit bridge  12  by way of an input port  16  and flows into the bridge  12  through input line  16   a . Advantageously, a one-way check valve  18  prevents pressurized fluid from escaping and back-feeding a supply pump (not shown) or pressure or pressure source. The valve  18   may be a solenoid actuated valve. An output port  20  provides regulated fluid flow from the bridge  12  via output line  20   a  to a load, such as a hydraulic motor (not shown) that supplies mechanical power to an electric generator, for example. The hydraulic circuit  10  further includes at least one accumulator, shown generally at  22 , and comprising a pressurized chamber  22   a  and a fluid storage chamber  22   b . The accumulator  22  supplies fluid to the bridge  12  by way of an accumulator output line  22   c . The accumulator  22  may be any type of accumulator such as, for example, a bladder-type, diaphragm-type, piston-type, or metal bellows type and may be any suitable number of accumulators. A reservoir  24  is connected to the bridge  12  by tank line  24   a  to permit accumulator discharge, if necessary or desired. 
     When valves  14   a  and  14   b  are activated to permit fluid flow therethrough, flow of stored energy in the accumulator  22  passes through valves  14   a  and  14   b  to the output port  20  allowing the load to be powered by the stored energy. In the event that the pressurized fluid from the input source  16  is intermittent or insufficient to supply stand-alone power, additional energy is supplied by the accumulator  22 . The energy management portion of the hydraulic circuit  10  is configured to direct available energy from the input source  16  to drive the load and augment the stored energy supply. Alternatively, if the input source  16  of pressurized fluid is abundant, the input  16  may drive the load demand and add fluid into the accumulator  22 . If the accumulator  22  is full and unable to accept additional fluid, the input supply may be deactivated and the accumulator permitted to discharge to a predetermined charge state before reactivating the input source  16 . To discharge the accumulator  22 , valve  14   d  is activated to permit fluid flow from the accumulator output line  22   c  to the tank line  24   a  and the reservoir  24 . 
     The hydraulic circuit  10  may also include a controllable venting system that allows oxygen in proximity of the hydraulic circuit  10  to be lowered upon the occurrence of a fire or extreme heat condition, thus extending safe operation of the hydraulic circuit  10 . 
     Referring now to  FIG.  2 A , a schematic illustration of a hydraulic cell is shown generally at  26  and includes one or more of the hydraulic circuits  10  of  FIG.  1   . In the illustrated embodiment, a plurality of accumulators  22  are connected to the bridge  12  by the accumulator output line  22   c . Each of the accumulators  22  is connected to the output line  22   c  through an output regulator  28 . The regulator  28  is configured to control any of fluid flow rate, pressure, and/or flow direction. The regulator  28  may be activated based on the load demand required, individually, as a cascading output from each accumulator, or as a group. The pressurized chamber  22   a  of each accumulator  22  is charged with a compressible medium, such as an inert gas like nitrogen (N 2 ), though any suitable gas may be used. The pressurized chambers  22   a  of each accumulator  22  are connected to a vent line  30  in order to regulate or eliminate the pressure level of the gas. The vent line  30  may be regulated by one or more release valves  32  and  34 . Alternatively, each accumulator may have a release valve connected from the pressurized chamber  22   a  to the vent line  30 . 
     In the event of an accumulator  22  failure or fluid piping failure, a particular accumulator  22  or any combination of accumulators  22  may be disabled by venting the pressurized gas therein. The affected accumulator  22  may be fluidly isolated by its associated regulator  28  and depressurized by the release valve  32  or  34  connected thereto. In the event of a system maintenance activity, the vent line  30  may be used to charge the accumulators from a charging source, such as by a source of pressurized nitrogen or by an air compressor when the inert gas is ambient air. This would permit remote location use and maintenance with minimal support supplies. Advantageously, the hydraulic circuit  10  is configured such that charging sources may be added or removed while the hydraulic circuit  10  remains in operation. Further, the hydraulic circuit  10  is configured such that charging loads may be added or removed while the hydraulic circuit  10  remains in operation. 
     Referring now to  FIG.  2 B , a first alternate embodiment of the accumulator  23   a  is shown as part of an accumulator system  23 . The accumulator system  23  also includes a gas pressure vessel or charge tank  23   b . The accumulator  23   a  includes a movable barrier, such as a piston  23   d  therein that divides the interior of the accumulator  23   a  into the fluid storage chamber  23   e  (the upper portion of the accumulator  23   a  when viewing  FIG.  2 B ) and a pressurized chamber  23   f  (the lower portion of the accumulator  23   a  when viewing  FIG.  2 B ). The fluid storage chamber  23   e  is connected to the accumulator output line  22   c . In the illustrated accumulator system  23 , the charge tank  23   b  is fluidly connected to the accumulator  23   a  via a fluid conduit  23   c  and also fluidly connected to the vent line  30 . The accumulator system  23  may include any desired number of accumulators  23   a  and desired number of charge tanks  23   b , as determined by system requirements. 
     One end of each accumulator  23   a  and each charge tank  23   b  may include safety hardware  23   g , such as pressure relief valves, pressure soft plugs, and/or engineered leak/blow-off sections mounted thereto. 
     Referring now to  FIG.  2 C , a second alternate embodiment of the accumulator  25   a  is shown as part of an accumulator system  25 . The accumulator system  25  is similar to the accumulator system  23  and includes a gas pressure vessel or charge tank  25   b . The accumulator  25   a  includes a movable barrier, such as a piston  25   d  therein that divides the interior of the accumulator  25   a  into the fluid storage chamber  25   e  (the lower portion of the accumulator  25   a  when viewing  FIG.  2 B ) and a pressurized chamber  25   f  (the upper portion of the accumulator  25   a  when viewing  FIG.  2 B ). The fluid storage chamber  25   e  is connected to the accumulator output line  22   c . In the illustrated accumulator system  25 , the charge tank  25   b  is fluidly connected to the accumulator  25   a  via a fluid conduit  25   c  and also fluidly connected to the vent line  30 . The accumulator system  25  may include any desired number of accumulators  25   a  and desired number of charge tanks  25   b , as determined by system requirements. 
     One end of each accumulator  25   a  and each charge tank  25   b  may include safety hardware  25   g , such as pressure relief valves, pressure soft plugs, and/or engineered leak/blow-off sections mounted thereto. 
     Referring now to  FIG.  3   , there is illustrated an energy management pod, shown generally at  36 . The pod  36  includes the plurality of cells  26  fluidly connected to a pod manifold  38 . The manifold  38  includes docking ports, shown generally at  40 , that provide fluid coupling of the bridge  12  of each cell  26  to pod output and return lines  42  and  44 , respectively that power the intended load, such as an electric generator and/or couple the vent lines to a single pod output/input. The cells  26  and the accumulator  22  or the accumulator systems  23  and  25  may be palletized. Thus, the cells  26  are configured such that the accumulator  22  or the accumulator systems  23  or  25  may be mounted on, and supported by, a surface  27  of the cell  26  (the upwardly facing surface when viewing  FIG.  3   ). The cells  26  provide a foundation that reinforces the a base of the accumulators  22  and the accumulator systems  23  and  25  when, in the event of a direct pressure release or explosion, energy is directed upwardly toward the safety hardware  23   g  and  25   g . 
     The manifold  38  may include fluid regulating valves or check valves to permit connected cells to operate when one or more are disabled. The cells  26  may be fluidly isolated from the manifold  38  and removed or added in a plug-and-play arrangement. This ability to remove or add cells  26  provides for a system that may be reconfigured or resized based on the demand required, the operational status of the system, and/or the external energy source availability. In addition, several energy management pods  36  may also be linked together to form an even larger energy management system. 
     Additionally, the manifold  38  may be configured as a modular manifold, as shown as  138  in  FIG.  4 A . The modular manifold  138  includes a plurality of manifold segments  139 , each of which includes docking ports  140 . The docking ports  140  provide fluid coupling of the bridge  12  of each cell  26  the energy management pod  36  output and return lines  142  and  144 , respectively, that power the intended load. Thus, the modular manifold  138  may be scaled by adding or removing manifold segments  139  allowing for the addition or removal of palletized cells  26 . 
     Referring now to  FIG.  4 B , the energy management pod  36  may be configured as a pipe system  150  rather than a manifold. The pipe system  150  includes a plurality of pipe segments  152 , each having a plurality of pipes  154 . In the illustrated embodiment, each pipe segment  152  includes four pipes  154 , each pipe  154  having an opening defining a docking port  156 . One pair of pipes  154  define the output lines  158  and one pair of pipes  154  define the return lines  160 . 
       FIG.  5    illustrates an alternate embodiment of the hydraulic circuit, shown generally at  100 . The circuit  100  forms a basic control circuit for the hydraulic cells, discussed below. The hydraulic circuit  100  includes the hydraulic-based Wheatstone bridge, shown generally at  112 . The hydraulic-based Wheatstone bridge  112  is similar to the bridge  12  and includes solenoid actuated valves  114   a ,  114   b ,  114   c , and  114   d . The valves may be any type of hydraulic flow control valve, such as check valves, spool valves, ball valves, and the like. In the illustrated embodiment, the valves  114   a - 114   d  are one-way check valves. Each of the valves  114   a - 114   d  may be actuated to permit flow bi-directionally by activating the solenoid portion of the valves. 
     Energy, in the form of pumped hydraulic fluid, enters the circuit bridge  112  by way of an input port  116  and flows into the bridge  112  through input line  116   a . Advantageously, a one-way check valve  118  prevents pressurized fluid from escaping and back-feeding a supply pump (not shown) or pressure or pressure source. The valve  118  may be a solenoid actuated valve. An output port  120  provides regulated fluid flow from the bridge  112  via output line  120   a  to a load, such as a hydraulic motor (not shown) that supplies mechanical power to an electric generator, for example. The hydraulic circuit  100  further includes at least one accumulator, shown generally at  122 , and comprising a pressurized chamber  122   a  and a fluid storage chamber  122   b . The accumulator  122  supplies fluid to the bridge  112  by way of an accumulator output line  122   c . A reservoir  124  is connected to the bridge  112  by tank line  124   a  to permit accumulator discharge, if necessary or desired. 
     When valves  114   a  and  114   b  are activated to permit fluid flow therethrough, flow of stored energy in the accumulator  122  passes through valves  114   a  and  114   b  to the output port  120  allowing the load to be powered by the stored energy. In the event that the pressurized fluid from the input source  116  is intermittent or insufficient to supply stand-alone power, additional energy is supplied by the accumulator  122 . The energy management portion of the hydraulic circuit  100  is configured to direct available energy from the input source  116  to drive the load and augment the stored energy supply. Alternatively, if the input source  116  of pressurized fluid is abundant, the input  116  may drive the load demand and add fluid into the accumulator  122 . If the accumulator  122  is full and unable to accept additional fluid, the input supply may be deactivated and the accumulator permitted to discharge to a predetermined charge state before reactivating the input source  116 . To discharge the accumulator  122 , valve  114   d  is activated to permit fluid flow from the accumulator output line  122   c  to the tank line  124   a  and the reservoir  124 . 
     Additionally, the hydraulic circuit  100  includes a second Wheatstone bridge  112  fluidly connected to the pressurized chamber  122   a  of the accumulator  122 . In this configuration, the input ports  116  and the output ports  120  may be used to transfer pressurized gas between one accumulator  122  and one or more additional accumulators  122  to modify the pressure or storage capability of the connected accumulators  122 . 
     Referring now to  FIG.  6   , a portion of the hydraulic cell  26 , such as shown in  FIG.  2 A  is shown and includes the bridge  12  having the input port  16 , the output port  20 , and the accumulator output line  22   c . The hydraulic cell  26 , and its associated bridge  12 , may be one of a plurality of hydraulic cells  26 . The illustrated embodiment also includes the accumulator system  25 . The accumulator system  25  includes the accumulator  25   a  and the charge tank  25   b  connected by the fluid conduit  25   c . The accumulator  25   a  is connected to the output line  22   c  via the output regulator  28 . As descried above, the output regulator  28  is configured to control any of fluid flow rate, pressure, and/or flow direction. 
     As described above, the charge tank  25   b  is connected to the vent line  30  in order to regulate or eliminate the pressure level of the gas. The vent line  30  may be regulated by one or more release valves  34 . Additionally, release valve  32  may be positioned between the charge tank  25   b  and the vent line  30 . 
     Referring now to  FIG.  7   , a series two accumulator systems  25  are shown with an additional charge tank  25   b . As shown in  FIG.  6   , the accumulators  25   a  are connected to the output line  22   c  via output regulators  28 , and release valves  32  are positioned between the charge tanks  25   b  and the vent line  30 . The vent line  30  is regulated by a release valves  34 , which further regulates the flow of pressurized gas to the additional charge tank  25   b . It will be understood that any number of accumulator systems  25  and any number of additional charge tanks  25   b  may be provided. 
     Referring again to  FIGS.  5  through  7   , the hydraulic circuit  100  having the illustrated embodiments of the accumulator system  25 , regulators  28 , and release valves  32  and  34  have advantages over conventional hydraulic circuits. For example, it the event that available charge gas for the hydraulic circuit  100  is less than a required system operating pressure, gas may be fed into the circuit bridge  112  to directly fill the charge tank  25   b  and the gas side of the accumulators  25   a . The hydraulic circuit  100  as shown in  FIG.  5    will then start charging the fluid side of the accumulators  25   a  closest to the gas source, thus causing the pressure in all the accumulator systems  25  to increase. 
     This process may continue until the yet dry accumulators  25   a  reach a desired operational pressure with a slight over-charge. The full pressure dry accumulators  25   a  may then be closed off from the gas charging system and the fluid in all the wet accumulators  25   a  may be drained to the reservoir  124  or via the valve  118 . The accumulators  25   a  having lower pressure may continue to be filled with the lower pressure from the circuit bridge  112  and the cycle may continue until only one accumulator system  25  as a pressure below full charge. The surplus charge in all the other accumulators  25   a  in the hydraulic circuit  100  may be drained into the undercharged accumulator systems  25 , thus creating a fully pre-charged hydraulic circuit  100  ready for operation. 
     Further, in the event that one or more accumulators  25   a  is damaged or otherwise fails, all of the accumulators  25   a  except the damaged accumulator  25   a  will closed from the circuit bridge  112  via the regulator  28 . The damaged accumulator  25   b  may then drain safely either through the valve  118  and the input port  116 , or to reservoir, as determined to be the safest approach by a hydraulic circuit  100  controller. 
     Significantly, if a fluid leak is detected into the gas, the fluid will be drained to the reservoir  124 . If a failure is detected in the charge tank  25   b  or the gas side of the accumulators  25   a , the gas will be vented to the atmosphere via the release valves  32 . 
     Advantageously, the various embodiments of the hydraulic circuits  10  and  100  described above are configured to allow the user to test the charge and discharge characteristics of the accumulator  22  or the accumulator systems  23  and  25  without taking the overall system off-line at any time. Each of the cells  26  may be isolated or quarantined from additional cells  26  in the hydraulic circuits  10  and  100  to allow safe operation to the rest of the hydraulic circuits  10  and  100  even if failure of the quarantined cell is catastrophic. 
     Each cell  26  may be configured to allow the cell  26  to neutralize itself automatically should it be determined unsafe to remain operational. Each cell  26  may also be configured to be neutralized manually should a qualified person in proximity of the hydraulic circuits  10  and  100  determine that the hydraulic circuits  10  and  100 , or portions thereof, are unsafe or in an environment that is unsafe for continued operation. The hydraulic circuits  10  and  100  may further be configured such that a cell  26  may be neutralized remotely should an authorized person with access to the hydraulic circuits  10  and  100  determine that the hydraulic circuits  10  and  100 , or portions thereof, are unsafe or in an environment that is unsafe for continued operation. 
     The hydraulic circuits  10  and  100  may be configured such that cells  26  may be added or removed therefrom during operation of the hydraulic circuits  10  and  100 . 
     The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.