US 20070258834 A1
The present invention is a system and method for managing compressed gas as an energy storage medium for providing power to vehicle uses. Compressed air has many pneumatic uses both inside and outside of vehicles and an Air Hybrid engine a source of compressed air energy for storage. This source of compressed air energy is stored, managed, and used in many methods and devices. The gas storage system presented is distributed over multiple storage units coupled to a gas flow network for control storage and use of the compressed gas.
1. A system for storing and managing compressed gas in a vehicle, comprising:
an engine having selectable cylinder compressed gas,
at least one compressed gas storage unit,
at least one pressure sensor for determining gas storage unit pressure,
compressed gas storage units coupled to engine cylinder for channeling bi-directional gas flow,
programmed logic for bi-directional flow control channeling gas from a programmably selectable cylinder to programmably selected storage unit and from the storage unit to the cylinder,
whereby compressed gas from dynamically selected individual cylinders can be flowed to disparate storage units for alternate on or off vehicle uses or redirected back to a selected engine cylinder for further compression or use.
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9. An energy storage and management system for compressed gas, comprising:
computer readable memory and at least one processor;
sensors measuring gas state at pre-determined gas locations;
sensor data in communication with processor;
compressed gas sources;
a plurality of compressed gas storage units;
a net work of channeling conduits, headers or plenums coupling the compressed gas storage units via electronic controlled valves;
logic stored in memory for enabling a computer application, under the control of a processor, to perform:
receiving compressed gas data from sensors,
determining compressed gas target locations,
determining compressed gas state,
identifying valves isolating a channel from compressed gas unit to target location,
actuating the opening and closing of electronically controlled identified channel valves, and
executing the logic to manipulate valve components channeling gas flow from the plurality of gas storage sources to the target locations at the gas state required.
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15. A method of storing and managing a compressed gas in a vehicle, comprising the steps of:
programmably identifying sources of individual cylinder compressed gas from an engine, identifying capacity available storage units,
selecting identified units based on a pre-determined pressure,
allocating a plurality of compressible gas storage units operatively connected with flow controlled through electronically controlled valves, for controlling gas flow from engine compressed air sources and to the allocated storage units,
accepting compressed gas from a identified compressed gas sources one or more pre-determined identified units,
accepting data from channel and storage gas pressure sensors,
storing the compressed gas in the allocated units, and
flowing gas from compressed gas source to storage unit or from storage unit to selected engine cylinder through a gas channel network programmably controlled by electronic controlled valves,
whereby compressed gas from engine generated sources can be directed to disparate alternate on or off vehicle uses or redirected back to the engine for further compression or use.
This invention generally relates to compressed gas storage systems for vehicles, and more particularly, to intelligent management of compressed gas as stored mechanical and fuel energy for multiple alternate uses and benefits.
With the advent of very fast digital valves, compressed gas can be applied in a continuous or analog sense as it is in current applications, or as impulse, or digital sense. Digital pneumatics is not currently used in applications, but can take better advantage of fluidic power efficiencies and resonance character of devices. Mostly fluidic transients are unwanted forces which must be designed around. However, fluidic transients in the form of timed pulses can be a powerful and very efficient method of energy delivery which is not currently exploited.
Compressed air has many pneumatic uses both onboard and off board vehicles. As the Air Hybrid engine develops, so does the availability of mobile compressed air sources. Most current Air Hybrid or Air Power Assist vehicle designs have an air storage tank to facilitate the generation of compressed air from braking and slowing the vehicle momentum, to transferring the energy normally thrown away to a later re-acceleration. The current single storage tank is inadequate, unreliable, payload space consuming and unable to supply all the uses and storage mechanisms possible for its intelligent exploitation and accommodation to vehicle constraints.
The present systems have one or two large compressed air tanks. These require time to charge, during which the efficiency of the air hybrid is not realized. The shear size and placement of the tank consumes strategic vehicle volume or cargo space, displacing normally used and valuable vehicle payload. Moreover, a tank leak disables the entire air-hybrid system, rendering the engine ineffective until the leak is found and repaired. Thus the one large tank air-hybrid is unreliable and vehicle space wasteful. What are needed are smaller, less cargo consuming space and reliable compressed air storage. Moreover, the current large high pressure tanks add concentrations of added weight becoming a liability against vehicle fuel performance and maneuverability performance. What are needed are schemes for lighter tanks with adequate pressure outputs to hand disparate requirements on short notice. The tank storage capacity also limits the vehicle range in efficient use. But large size tanks prevents a more strategic placement onboard the vehicle. Currently vehicles have many “hollow” spaces which can otherwise hold air, if only it could accommodate the large cylinder tanks. What are needed are tanks which conform to available unused space in current vehicle bodies yet provide adequate compressed gas storage capacities.
Pressurized gases on board vehicles can serve many uses, and not only in engine fuel regeneration or in performance enhancement through oxygen enrichment. Gas fuels such as propane, compressed natural gas, butane and hydrogen are good candidates for alternate fuel sources. There are alternate utility uses for compressed air while the vehicle is mobile or stationary. What is needed are compressed air management systems which monitor and control the charging and discharging of compressed air to can provide alternate and reliable compressed air sources.
Turning to mobile compressed air uses, air shocks are devices which use compressed air to stiffen or dampen a vehicle suspension system. Adjusting air pressure can alter the stiffness of not only shocks, but many designed structures including vehicle body, bumpers, chassis and suspension. A source of available and variable compressed air can accommodate many such uses, uses that cannot be exploited with the one-tank designs of current air-hybrids because of limiting pressure, volume, capacity or combinations of those. Mobile uses of compressed air include but are not limited to vehicle structure and body stiffness manipulation from compressed air pressure, tire inflation, light weight pneumatic motors for vehicle components, seat comfort, bumper stiffness, air bags, shock assemblies, windshield wipers and washer, tire road air brushes, air foil and stabilizer enhancements, electronic controlled thrust vectoring, etc
Current electric hybrid vehicle employ large heavy and expensive battery banks to store the energy recaptured for regeneration and use in engine or onboard components. What is needed is a comparable compressed air energy storage system for air-hybrid vehicles, to intelligently store and manage the compressed energy.
The present invention discloses a system for storing and managing compressed gas in a vehicle having an engine with dynamically selectable cylinder compressed gas, at least one compressed gas storage unit, at least one pressure sensor for determining storage gas unit pressure, compressed gas storage units coupled to engine cylinder for channeling bi-directional gas flow, programmed logic for controlling bi-directional gas flow channeling gas flow from programmably selectable cylinder to programmably selected storage unit and from storage unit to cylinder, whereby compressed gas from programmably selected individual cylinders can flow to disparate alternate on or off vehicle uses or redirected back to a selected engine cylinder for further compression or use. The compressed gas storage units are coupled to a network of channels wherein electronic controlled valves using programmed logic maintain pressure ranges in selected gas storage units, cascading compressed gas flow to storage units in parallel or serial based on preset pressures, storage capacities and unit pressure. The compressed gas may be air or a fuel gas such as hydrogen or natural gas. Some embodiments include air as the compressed gas, and components as digital valves, wireless sensors and composite conformable gas tanks partitioned into cells and electronically managed.
Specific embodiments of the invention will now be described in detail with reference to the accompanying figures.
In the following detailed description of the invention embodiments, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description, in adhering to a fundamental mode and cycle of operation examples.
The presently disclosed system and method can be implemented using hardware, software or a combination of hardware and software. The disclosed system and method is comprised of hardware and electronic control components, which can be implemented using many different hardware configurations for applications as well as programmable control of features.
In general, embodiments of the invention provide a method and apparatus to allow a compressed air storage to be distributed and managed in a vehicle for multiple applications. The distributed and intelligent management of such a system overcomes many energy and utility challenges, providing many uses and benefits such as quick charge availability, compressed air storage versatility and reliability, reduced cost due, increased utility for disparate uses on-board and off-board the vehicle, stiffness variability for safety, ride comfort and other uses.
Since valves and stitches are electronically controlled, preset levels are adjustable, requiring basic programming logic monitoring pressures and opening/closing switches and valves. Upon filling a unit to capacity or a preset level, individual unit tank combined pressures can be used to pressurize a third stage bank 131 through another valve 119 and throttle orifice 121 or to provide an intermediate pressure compressed gas at header 135 for any number of alternate uses at lower or alternate use pressures. Another storage stage of lower presser storage 123 is received through the admitting valve 119 throttled 121 to the preset lower pressure in storage 123 bank stage 131. As with the other stages, the storage units can be in parallel, to increase reliability, safety, redundancy, and other advantages. A safety relief valve 127, is provided to vent 125 to atmosphere should the need arise to protect the equipment.
Schematic key symbols 150 represent the compressed Air Storage Tank (CAST) units, valves, an electronically controllable pressure regulator valve—one where response time is essential as several modes of operation may require engine piston following time responses with knowledge of pressures upstream and downstream of the valve, throttling orifice, pressure relief valve, check valves and electronic controlled switches. One skilled in the art will be capable of substituting for many of these components as they there are many ways of controlling gas flow and electronic controlled piping and gas storage are well known to those skilled in the art The schematic legend 150 will apply to
Three storage banks 210 207 215 are shown but more or less stages can be implemented. A cylinder-piston unit 201 acting in compression mode will compress the cylinder 201 gas, and will compel this compressed gas through a check valve 207 to a header or manifold 210 whereby it can be distributed to one or more storage first stage storage 235 units. This stage 210 storage bank most immediate to the cylinder 201 is in most embodiments likely be the highest pressure storage, and can be placed very near the engine, perhaps adjacent to the engine heads in insulated spherical-cylindrical compartments. During a pressurization or compression mode, a pressure control valve 205 actuating from an electronic control switch 211 controlled through control line 209 can receive the valve open or close signal and admit or receive gas flow through the check valve 207, compressed gas from the high pressure storage 235 through the valve port 203 or back to the cylinder for a re-compression to a higher pressure respectively, and in thus fashion repeated for pumping up or increasing pressure to storage pressure header 210. This cycle can continue until the storage pressure in the high pressure 235 stage reaches a preset level through the operation of the switch control lines 237 for high pressure storage valves 239. Multiple parallel tank units 235 can be used to provide redundancy and reliability, and also higher cumulative pressures at the header 210 should the need arise. These are isolated from the header manifold 210 pressure in this embodiment. Upon reaching a pre-set pressure, a switch 211 to open a valve 213 which will throttle 215 the pressure to a preset intermediate pressure at a header 207 which will supply pressurize to another stage bank stage 227. Switches 231 to valves 228 are electronically and individually controlled 229 to allow storage units 227 to receive or cease gas flow. Switch 209 is electronically controlled to flow gas via valve 211 to be throttled 213 to a lower pressure header or manifold 215 for storage 219 at lower pressures 215 or alternate uses from a lower pressure gas. These decisions are programmable using the switches 217 individually controlling 225 flow to gas storage units 219. Storage units 219 can be duel ported with valves 221 for discharge or intake and discharge, to facilitate the alternate use scheme designed for a storage unit bank or stage of pressurization. Electronic control 223 of the valves 221, as in the control 237 239 of other stage pressure units is by individual storage unit, to facilitate yet another aspect of the invention.
Upon filling all parallel storage units to capacity at a individual pre-set levels, lower pressure storage units can be fed overflow pressurized gas. Although parallel units appear symbolically identical, their strength, size and capacities may differ, even in a common bank. They also may spring leaks, which will require that they be isolated for non-use and flagged for repair. Alternatively, another aspect of the inventions provides for lower pressure tanks through transient pressure wave combinations. This is done through time pressure releases from known unit pressures and pressure wave travel time which upon convergence an a target location, pressure waves combine lower pressures to achieve a higher pressure for storage or use.
As with the all banks, the storage units can be in parallel, to increase reliability, safety, redundancy, and other advantages, but they can also be configured in serial for other benefits.
The duct or channels connecting the cells can also vary depending cell design pressures and expected required output pressures and flows. For example, if the cell pressures are high and the required flow is high, critical or chocked flow conditions may arise. For this reason, a network of channels may be necessary to avoid the choke locations and conditions. The network 303 305 will allow the known cell location and distance to output required location to be calculated along different paths. The acoustic character of the gas wave and speed are known which then allow a straight forward calculation of the flow along different paths. More valves 313 315 may be implemented along the channel network 303 305 for flow control as well, steering the flow along optimal and selected conduit paths.
CAS banks and individual cells in banks are programmably controlled with pressure sensor data, each cell and channel scanned for pressure data at the appropriate time for a real time response. Thus, cells losing pressure due to leaks, can be shut down and flagged for maintenance, without bring the whole storage system to a common mode failure when compressed gas is requested. CAS insulation will preserve the compressed gas energy in the cell for timely use.
Many other CAS cell charging and discharging algorithms are possible and for many other objectives. A primary objective may to be to delivery pressure to sink point or use orifice. A secondary objective in the algorithm may be to discharge or charge the cells in a particular order. For example to reduce the required cell wall strength requirements, cells may be structured inside other cells and so forth, such that the step differential increase in cell pressure is all that produces wall stresses and the incremental step charging and discharging never exceeds a lower cell wall stress as cells are charged and discharged in accordance to a particular sequence.
In a slab storage embodiment CAS bank 609 of cells, the channel geometries, temperatures, and cell pressures are known. Hence pressures in cell P1 601 and cell P2 602 are to be used to obtain a required pressure P3 for a pulse width W 637. The total pressure wave travel length from P2 602 to a common point is L2 615. The total travel distance from P1 601 to the common point is L1 617, the sum of X 603, Y 605 and Z 607. The pressure wave travel time dT1 637 and dT2 636 from P1 and P2 to the intersection point 639 could be determined by L1/c and L2/c respectively, where c is the acoustic speed in the gas at the temperature in the channel. For the
In some embodiments individual storage units or cells each have pressure sensors indicating the cell or storage unit pressure. These may also have a switch and valve under processor control, such that logic can be applied in real-time to engage the valves to release or acquire compressed gas. Many valve and switch configuration may suffice and most recently digital valves have become available and offer many advantages. There as some digital valves and some used in the auto industry which are rated at 10,000 cycles/sec. Pressure pulses traveling at acoustic speeds of 1100 feet/sec can easily be pulsed in digital pulse trains also, tuning the pressure pulse for certain applications requiring a resonant or tuned pressure pulses. The algebra of pulse addition and subtraction then becomes an arithmetic exercise easily programmed in logic by those skilled in the art, where the state conditions, travel lengths and paths, channel dimensions and wall properties and such parameters are known. In some embodiments sensors and components can be electronic, wired or wireless controlled. The illustration shows that a gas pressure pulse can be released, and since the pulse travel time is known by its acoustic properties and the distance is known from source to sink, then the time of opening and duration for cells can be calculated and programmably implemented to produce a summed pressure at any intersection or application sink location. As mentioned above, the channels connecting the compressed air storage (CAS) cells and banks can be in a channel or conduit network with flow control valves to allow selected paths from cells to sink locations at real-time determined pressures and flows. Pressures can be analog pneumatics or digital pulses, depending on design and design requirements and applications. Pressure, pressure pulses and pressure pulse trains of various frequency, duration and amplitude can be pre-determined and obtained through valve actuation from an array of compressed air units coupled with a connecting network of communication tubes or conduit and electronic valve actuation under processor control. Air hammers and variable pressure pulse acceleration from impulse pressure are also possible applications.
The advantages of such systems are that 1) no individual CAS cells need have the required sink or application pressures or volumes as application pressures of many kind can be achieved algebraic combinations from individual cells, 2) reliability is increased because cells can be brought on or taken off line to deliver component pressures and flows, 3) the combined tank banks can be conformably manufactured for most curved shaped volumes, 4) the CAS bank arrays can be made lighter and cheaper for equivalent volumes by using inherently stronger but more efficient geometry such as the honeycomb structure, 5) higher sink pressures are attainable from lower CAS pressures, 6) quicker charge time because CAS cells can be charge ready will some are not, net the bank charge cell locations are know and can be called upon to deliver pressure, 7) the CAS bank pressures can be varied to provide a variable structural stiffness, yet another useful property offered for no extra cost.
Phased Array Pressure Pulse (PAPP)
Most current pneumatic systems use compressed air in an analog fashion, with continuous gas pressure dynamics. We introduce the capability to shape pressure pulses and to combine pressure pulses by timing for constructive or canceling pressures where required. An embodiment of the invention provides digital pulse or impulse pressure intelligently. PAPP can provide total pressures which are larger than individual storage unit pressures by timing the transients such that small pressure pulses together from selected storage cells can additively attain larger pressures at known target location to deliver a summation or pressure resultant pulse. Thus a digital form of pneumatic application is introduced. This is done knowing the distance that a pressure wave travels in a known medium, knowing the acoustic properties of the medium, selecting the tanks with known pressure and location and sequencing the valve openings to channel a pressure pulse to the target location, combining the transient pressure pulses where they are pre-determined to meet such that their transient pressure pulses are additively directed. Thus it can still be useful to have source pressures in any one tank unit which are low in pressure. Furthermore, bypassing locations which would otherwise serve as choke points can be accomplished by placing valve to open and close specific flow channel, using the combination peak pressure pulses only at location and times needed. Storage unit costs can thus be lower because thick walled CAS volumes may not be needed for some applications and embodiments, utility is higher because applications vary in pressure and flow requirements but can be managed smartly with programmable controls. For example, a PAPP application can enable an air cannon type application, where impulse pressures or pressure pulses can be delivered on demand in a particular acoustic pulse pattern, without expensive high pressure metal cylinder storage units acting in an analog or continuous pressures.
In another embodiment, a purely air impulse engine is envisioned. The PAPP can be programmed such that large pressure pulses are delivered to the appropriate cylinder intake ports for initiation of an intake or power stroke. Thus a two stroke impulse air engine can very efficiently make use of compressed air storage energy by not having a continuous bleeding of compressed air analog fashion, and the compounding energy contribution from additive pressure pulses in digital fashion in concert with the engine cylinder power strokes.
A network of compressed gas conduits 814 have valves, switches and sensors to programmably maintain compressed air energy and distribute to the demanding application. The bumpers 811 or any vehicle collision surface can be strengthened or stiffened by use of pressurization. Mature applications such as air bags 805, seat softness 804, and air windshield wipers 807 are other practical uses for on board vehicle compressed air applications. Air motors, piston actuators and conventional mechanical pneumatic components can replace electric motors using weighty metal coils metal rotors, and many of the electric motors applications in vehicles, with the advantage of weight reduction using non-metallic materials. Moreover, most current vehicles carry many electric motors in implementing all manner of features which can be replaced by compressed air driven motors, pistons and other mechanical devices. Electrical mechanisms add significant weight to the vehicle, as well as cost of maintenance and replacement, extra fuel required to haul extra weight, etc. Thus sources of compressed air on board a vehicle with an programmable compressed gas management systems can provide an analogous solution to the electric hybrid not only from the propulsion efficiency through regeneration, but also from a gross vehicle weight reduction by eliminating heavy battery banks, metal wire, wire coils, cores and metal rotors, and without a reduction in applications, features and vehicle advantages. Many additional compressed air applications can be served with mobile compressed air supplies, as pneumatic tools and recreational equipment industry growth will attest.
The frame chassis itself can become a part of the distributed CAS, with an additional benefit of a potentially adjustable stiffness and frame strength capacity to withstand higher vehicle forces and or damaging collision frequencies by tuning stiffness to an otherwise too stiff a frame. The control signal lines, not shown, and components are designed into the frame to provide ease of manufacturing as well as maintenance.
In an embodiment of the invention, a vehicle tubular frame 901 can act as a chassis but can also have a tubular roll bar 907 built in as well, providing more storage volume for compressed gas. In addition to providing a vehicle platform, the frame can house a compressed gas storage system. In an embodiment of the invention, cylinders 901 905 are separated by valves 903. The valves and cylinders can be an integral part of the tubular frame or not. Since the cylinders can be pressurized, their stiffness can be variable, adding another function to a tubular frame, adjustable flexibility or stiffness. The cylinder compartments can be directly connected one to another serially, allowing an orderly discharge of pressure and re-charge serially, with check valves or electronic controlled valves. In the alternative, cylinder valves can be configured to output and input in parallel, by running conduits or channels outside of the frame to the input source or output manifold. Since the tubular frame would naturally lend itself to high pressures, the frame can serve as a high pressure gas storage system, it following that the source could be the engine cylinders for gas fuels or a sink for cylinder high pressure air. Because the valves are electronically controlled and monitored, as they are emptied of a fuel gas, they can also be used as storage for compressed air, regenerating energy from vehicle braking or down hill slowing. Not shown are insulation of the storage cylinder units, providing an adiabatic environment for the gas where necessary.
In one embodiment 1011 illustrates a tube frame integrated valve, where storage units Tank1 1009 and unit Tank 2 1007 are separated by a slider or rotator valve 1001. The valve is integrated fully into the tubular frame 1006 wall, separated by a double in tube valve wall 1003. An orifice 1005 provides an alternative flow path from Tank 1 or Tank 2 to outside the frame tube. The slider/rotator is electronically actuated for flowing gas between units or directing gas out through the port 1005.
In another frame tube unit valve embodiment 1019 illustrates an valve outside tube frame construction, the units Tank 1 1017 and Tank 2 1015 are separated by a physical wall 1018, and communicate flow through an out of frame tube valve 1014, which can flow Tank2 gas through Tank2 spigot 1013 to manifold 1016 or alternatively to Tank 1 1017 via Tank 1 spigot 1021. The valve 1014 is electronically controlled and pressure sensors giving gas pressures in separate units are used in logic to flow gas in the state and direction programmed.
Another tubular frame valve embodiment 1030 illustrates an a valve partially in the tubular frame body. Units 1029 1027 are separated by an integrated tube valve 1031 partially exposed outside of tube outside diameter. The valve separates the storage units 1029 1027 by a double wall 1025 and allows flow through directly across to adjacent unit or purge to outside of tube frame. As with the other units, the valves are electronically controlled, but with failsafe mechanisms.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
Other aspects of the invention will be apparent from the following description and the appended claims.