CN108602433B

CN108602433B - Compressed natural gas carrier safety system and method

Info

Publication number: CN108602433B
Application number: CN201780011098.2A
Authority: CN
Inventors: D·麦克尼克拉斯
Original assignee: D Maikenikelasi
Current assignee: D Maikenikelasi
Priority date: 2016-01-16
Filing date: 2017-01-14
Publication date: 2022-04-12
Anticipated expiration: 2037-01-14
Also published as: KR20180104003A; AU2017208021A1; JP2019509202A; BR112018014350A2; EP3402690A4; AU2017208021B2; JP6956726B2; EP3402690A1; CN108602433A; WO2017124051A1; CA3011475A1

Abstract

A multiple redundancy system that prevents a driver from starting and/or moving a vehicle when a compressed natural gas filling system is not properly and completely disconnected from the vehicle. One or more sensors in combination with one or more optional micro-switches lock the ignition of the vehicle or otherwise prevent the vehicle from starting and/or moving. For different safety levels, different combinations of sensors may be used, with the lowest level having a single proximity sensor that senses the presence or absence of a high pressure fill hose. Further, a multiple redundant system protects fueling of rockets, aircraft and other vehicles using Liquefied Natural Gas (LNG) and an oxidizer such as liquefied oxygen. One or more sensors in combination with one or more optional micro-switches detect any leakage, fire or explosion hazards, thereby quickly locking further refuelling. For different security levels, different combinations of sensors may be used.

Description

Compressed natural gas carrier safety system and method

Technical Field

The present invention relates generally to the field of vehicle safety and compressed natural gas, and more particularly to safety systems related to fuel vehicles powered by compressed natural gas.

Background

Natural gas is becoming a rich resource in the united states and several other countries. It is estimated that the natural gas reserves in the united states exceed the oil reserves of saudi arabia in terms of the year of energy supply.

To make efficient use of this resource and replace crude oil, the carrier must use natural gas. Many fleet operators are turning their vehicles to natural gas because the internal combustion engines can operate well on natural gas with minor modifications.

Natural gas is commonly supplied in two different forms: 1) as a compressed gas; and 2) as a liquefied gas. Although liquefied gases are more efficient in terms of the amount of gas that can be supplied in a single tank, they are very dangerous to handle and require highly specialized instrumentation to fuel them and actually use them. On the other hand, compressed natural gas is relatively easy to fuel and utilize. Compressed natural gas may be supplied in pressure bottles between 3000psi and 4000 psi. How to handle and fill such bottles is well known in the industry. A natural gas "service station" can fill a carrier tank (pressure bottle) within minutes using a similar high pressure air filling technique. Carrier tanks containing 100-. The tank may be protected from direct impact in an accident.

Many homes and businesses in the united states use pipelines to carry natural gas for cooking and, in many cases, to carry heating. Most americans have at least one vehicle or other vehicle, and many homes have multiple vehicles. This combination directly indicates that a natural gas carrier can be filled at night at home or at a small business location for use the next day. Refilling at night is facilitated because even a large compressed natural gas tank does not last as long between refills as a typical gasoline tank does. The carrier owner may also use a natural gas filling station; however, this may be more convenient for long trips. Most people prefer not to fill their vehicles at a gas station for 5-10 minutes. Although replaceable tanks are also possible, these tanks require more logistics than simple fixed on-board tanks. Even with replaceable canisters, the vehicle owner may still have to wait a considerable amount of time to refill at the station, as compared to the current use of gasoline.

Currently, at least one automotive manufacturer is supplying a compressed natural gas carrier and a domestic compressor for a filling carrier. National fire codes currently prohibit the rapid filling of large gas tanks in homes or compressors. In view of the current standards, the domestic compressor will be connected directly to the vehicle via a high pressure hose, and the vehicle will take several hours to fill (depending on the size of the on-board tank). Again, this will be done very conveniently at night. The same arrangement is also applicable to small businesses, particularly those with fleets of vehicles.

However, as many individuals fill their garages or their places of business with natural gas vehicles at night, the likelihood of a very serious accident, the so-called drive-off accident (drive-off accident), is increasing dramatically. This means that the driver tries to drive out with the high-pressure filling hose still connected to the vehicle. Such an accident in a home garage can be catastrophic if the fittings or valves on the car are damaged, or if the compressor is pulled away from the home natural gas source. In either case, a significant amount of gas may escape into the garage, creating a fire or explosion hazard. Furthermore, even in a "mild" drive-out accident, the driver stopping before disconnecting the hose or fitting may put pressure on the filling hose and may cause a small, difficult to detect gas leak. Such small leaks may cause the garage to fill with gas in the morning.

Natural gas contains primarily methane and is therefore lighter than air. The natural gas leaked from the garage is filled into the garage from top to bottom. The explosive mixture of natural gas and air is between about 5% (for pure methane) and about 15% -20%. Many garages have stoves and water heaters with open flames. When the garage is filled with natural gas, it can be easily ignited by a stove or water heater on the elevated base (fire codes require that open fire devices in the garage be mounted on the base to avoid gasoline vapor from collecting along the floor due to gasoline leakage from the car). This is an ideal case of a garage explosion. Thus, any event that might cause the release of natural gas or cause a gas leak becomes a significant hazard. A driving accident is such an event.

Some techniques have been reported in the prior art to prevent the start of a gasoline vehicle at a petrol station while the filling nozzle is still in the gas tank inlet. This includes, inter alia, U.S. published application No. 2002/0162601 and U.S. patent No. 5,720,327. Other techniques have been devised to prevent the pumping of gasoline or other fuel when the fill hose is not in the fill inlet. This includes, inter alia, U.S. published application No. 2008/0290152 and U.S. patent No. 4,227,497.

While these prior art techniques are useful for gasoline, they do not address the problems associated with filling vehicles with high pressure compressed natural gas at home or in commerce. In particular, compressed natural gas tanks are filled to very high pressures (between 3000psi and 4000 psi). Leakage or disconnection of fittings or valves on such pressure vessels can cause a large pressure explosion that acts like a bomb (which can occur in any compressed gas including air). In addition, extremely small leaks at high pressures can result in significant gas evolution. For example, an explosion can may send metal fragments in all directions with sufficient force to penetrate the vehicle's outer shell and the operator's compartment. This may occur before a fire is present. Thereafter, the smallest sparks can ignite the now explosive and highly flammable gas cloud, ruining the house or business. Even a quick disconnect of the hose is generally not a problem, as the driver may try to drive off very quickly, still damaging the fittings, tanks, hoses, compressor and/or natural gas supply.

It would be highly advantageous to have a dual or triple redundant system and method that prevents the driver from activating the vehicle when the fill hose is connected and the safety valve is not in the correct position.

Disclosure of Invention

The present invention relates to a multiple redundancy system and method that prevents a driver from starting or moving a compressed natural gas carrier when a high pressure natural gas filling system is not properly and completely disconnected from the carrier.

In one embodiment of the invention, a plurality of electrical proximity sensors or other sensors are combined with one or more optional mechanical microswitches to lock the ignition of the vehicle together or otherwise deactivate the vehicle. For different levels of security, different combinations of sensors may be used, with the lowest level having a single sensor sensing the presence or absence of a fuel supply fitting. The highest level of safety according to the present invention is to have separate sensors such as proximity sensors on the fuel fill hose fitting, gas cap and manual safety or isolation valve, and redundant micro-switches on at least one component. The ignition, transmission or other functions may be locked by an electrical or mechanical locking device provided by the manufacturer to the vehicle computer, or by a simple series electrical circuit in the squib string. The safest system can use both technologies simultaneously.

Further, the vehicle's computer or another simple electrical circuit may provide a visual and/or audio indication that one or more sensors are indicating that a fuel hose is connected. Once the driver inserts the key into the ignition, the alarm will be activated. In the present invention, it is understood that one of the sensors may fail in a state indicating that the fuel hose is connected when the system is actually fully safe. In this very special case, the present invention provides the driver with a technique to override the sensor and start the engine or move the vehicle using the supplied override on a limited time basis. With this feature, the driver is allowed to drive to the mechanic to resolve the problem. This feature may be automatically disabled by the abuse prevention device after a predetermined number of uses (e.g., three) to prevent the driver from delaying the repair of the bad sensor. Finally, an optional breakaway fitting may be provided for a final level of protection, in addition to other features of the present invention.

Drawings

Referring now to the several figures which illustrate features of the invention:

FIG. 1A shows a block diagram of an embodiment of a high security locking system according to the present invention.

FIG. 1B shows a logic circuit that can combine sensor inputs.

Fig. 2 shows a detail of a filling fixture with a proximity sensor.

Fig. 3 shows the system of fig. 2 with the high pressure fill hose removed.

Fig. 4 shows a system similar to that of fig. 2-3 with an additional air cap sensor.

Fig. 5 shows a plate fill system with an isolation valve and three proximity sensors.

Fig. 6 shows the system of fig. 5 with an additional mechanical microswitch.

Figure 7 shows a motion and ignition system for use with natural gas fueling.

FIG. 8 illustrates an LNG/LOX refueling safety system.

To facilitate an understanding of the invention, several figures and illustrations have been presented. The scope of the invention is not limited to what is shown in the drawings.

Detailed Description

The present invention relates to a system and method for providing locking of an ignition device, transmission or other device of a mobile vehicle when a high pressure compressed natural gas fuel hose is connected to the vehicle and/or a filler cap is open. Fig. 1A shows a block diagram of an embodiment of such a system. The compressed gas fuel fitting 2 houses a high pressure fill hose 21 which allows filling through an isolation valve 22. The isolation valve 22 may be opened manually, or the isolation valve 22 may be opened mechanically when a panel cover or "gas cap" is opened. The sensor 4, which may be an electrical proximity sensor, senses the presence of the fitting part of the high-pressure filling hose 21. An optional second sensor 8 senses the panel or air flap opening. An optional third sensor 14 may sense the position of the isolation valve 22 (on a vehicle having such a valve). All sensors may be magnetic, optical or ultrasonic proximity sensors, or any other sensor, and any method is used to sense proximity, or whether a particular mechanical component is in a particular position. One or more optional mechanical microswitches 23 may provide backup for one or more sensors.

Another logic circuit 24 or other locking device may be a separate unit or part of the vehicle processor and may combine the inputs from all

sensors

4, 8, 14 and optional micro-switches 23 to generate a safety signal 25, which safety signal 25 will allow the vehicle to ignite to start the vehicle or otherwise allow the vehicle to move. Fig. 1B shows a schematic diagram of this circuit 24. Here, the signal of each sensor is amplified and conditioned and fed to an and logic circuit 26. If any of the sensors are in an unsafe state, the AND circuit 26 will not generate a "safe" signal. The particular circuit of fig. 1B assumes that the proximity sensor has a logic high when in proximity and the micro-switch has a logic high when the cover is closed. Any other logic level or configuration may be used. In particular, a program in a microcontroller or other processor may also make the determination. An or circuit may also be effectively used in place of an and circuit, as is well known in the art. Any circuit or program that combines sensor inputs to make a "safe" determination is within the scope of the present invention.

Fig. 1B also shows an override device 27, which override device 27 may be used to force a "safe" state when one of the sensors is in an unsafe state. This circuit is optional, but when provided, allows the driver to drive to the mechanic when the sensor fails. The counter 28 or other abuse-resistant device prevents the override from being used more than a predetermined number of times (e.g., three times) before the sensor is repaired. The counter 28 may be selectively reset whenever the sensor logic generates a safety signal. In this example, the driver may enter a special PIN code 29 to activate the override device and override the sensor. While providing this circuitry slightly lowers the overall safety threshold of the system, the act of performing an override may be difficult enough that it is not routinely used by the driver to avoid having to repair the failed sensor. Alternatively, the override device may only be used by an authorized mechanic. In this case, the driver will not be allowed to operate it. Although a simple override switch may be used, a PIN or bar code or any other unique identification 29 may be required for additional security. If a PIN is used, a PIN entry method, such as a keyboard or swipe card, may be used. If a bar code is used, a small bar code reader may be provided.

Fig. 2 shows a male can adapter 2 on a carrier with a coupled (typically spring-coupled) female fill-lock coupler 3 and a high pressure feed hose 1. The feed hose 1 is typically derived from a compressor or a storage tank. A proximity sensor 4 with an electrical connection 5 senses the presence of the feed hose (unsafe condition). The female lock coupler 3 typically has a connection/disconnection fitting that clamps the tank adapter 2 and makes a high-pressure leak-proof connection. It should be noted that the female priming locking coupler 3 may be a quick release, separate fitting. This would add a final mechanical precaution to the system, and in the event of somehow failing the rest of the system, the hose would be manually disconnected.

Fig. 3 shows the same arrangement, but with the feed hose 1 and the female locking coupler 3 disengaged and retracted from the male priming adapter 2 (safety position).

Fig. 4 shows the filling chamber 6 and the filling inlet cap 7 swung open on a hinge. The second proximity sensor 8 has a second feed 9. In an embodiment of the invention, this sensor 8 may be used alone or in combination with the feed hose sensor 4. An optional microswitch 20 is also shown.

Any type of sensor may be used with the present invention. Preferred sensors are magnetic or optical proximity sensors; however, other types of sensors, such as ultrasonic sensors, etc., may also be used.

Fig. 5 shows a different arrangement of the fuel filling system. This type of system is more common on trucks and large vehicles. The panel 13 opens and closes to allow access to the canister adapter 12. The isolation valve 10 may be manually operated or may be operated in conjunction with a lever 16 on the panel 13. A third proximity sensor 14 having a power feed 15 may be used to sense whether the panel is open or closed (and thus, if a lever 16 is used with the valve 10, whether the valve is open or closed). When the panel is closed, the valve 10 isolates the canister adapter 12 from the canister.

Fig. 6 shows the same embodiment as fig. 5, except for an optional microswitch 23 which has been added to the panel 13. This is a simple mechanical backup system that does not rely on proximity sensors. It should be noted that any of the proximity sensors shown in the various embodiments of the present invention may be replaced by a micro-switch or other mechanical device, or each proximity sensor may optionally be backed up with an additional micro-switch. Additionally, FIG. 6 shows an optional additional microswitch 21 on the isolation valve 10.

It should be noted that alternative natural gas leak sensors may also be included in the system of the present invention to provide an additional source of safety. Such a sensor may keep the vehicle in a deactivated state if an unreasonable concentration of free natural gas is detected. Such sensors may also alert on the vehicle or compressor. Any of the above described sensors or circuits may also communicate wirelessly, such as by radio or optically, with a lock or other logic. Finally, it should be noted that a processor having memory and stored programming may perform the logic functions of the lockout, override, and/or abuse-resistant devices. This could also be any digital or analog logic circuit or simple relay. In addition, an internet or network interface may be provided to report or record the status of the system remotely. This feature may be used for fleet operators to track safety, e.g., the number of attempts to drive off or override in locked conditions.

The present invention provides a multiple redundant system that enhances the safety of home or commercial fueling of compressed natural gas vehicles. The multiple redundancy system may also be used on vehicles that use propane or any other compressed gas fuel. A system having one or more sensors determines whether the fuel fill system is in a safe state. This may be a condition where the high pressure fill hose is removed, the refueling chamber inlet cover is closed, and any isolation valves are in the correct position. The lock may prevent the vehicle from starting when the system is not in a safe state or otherwise disabling the vehicle from moving. In order to enable the driver to repair a faulty sensor, an override device may be provided which allows to override the safety sensor and move the vehicle. This override device may be provided with an abuse-proof device that only allows the override device to be used a predetermined number of times before the override device itself is deactivated. This will prevent the driver from postponing the repair of the faulty sensor. An audio and/or visual indicator may sound or display when the driver inserts the key into the ignition in an unsafe condition, or alternatively, when the driver turns the key to start.

In the present disclosure, locking is any method, device, or technique that prevents movement of the vehicle, including a circuit or module that may deactivate the ignition or transmission or deactivate the vehicle in any other manner. Override is any method, device or technique that allows the carrier to move regardless of the lock (any override of the lock). An abuse-prevention device is any method, device, or technique that prevents an override from being abused by limiting the number of times the override device can be used, particularly a consecutive number of times.

When fuelling with natural gas, either compressed gas or liquefied gas, any excessive movement of the vehicle being fuelled (car, truck, train, ship, barge or any other vehicle) is not allowed. Such motion indication should cause the refueling operation to be shut down and, in many cases, cause automatic disconnection of all refueling lines from the vehicle and possibly release of one condition of the vehicle.

To detect omnidirectional vehicle movement/distance, multiple sensors may be used alone or in a cascade control system to perform different functions to perform vehicle locking or automatic fueling line disconnection. The use of one or more sensors in combination with one or more microswitches automatically mitigates excessive movement, starts locking and closes the isolation valve to prevent/disable fuel flow/transfer. The sensor(s) that detect excessive movement (above or above a predetermined stop limit), such as optical and/or ultrasonic sensors, may be sensors such as laser or radar measurement sensors, or may simply be accelerometers coupled to the processing unit to calculate the movement. The use of one or more of these sensors, or possibly multiple sensors, creates the safest condition to begin mitigating fuel transfers by keeping the other systems in a locked state and activating one or more audible and/or visual alarms. The fuel flow system may be restarted by an operator. Different carriers may require different parameters to initiate such motion locking. For example, a high degree of excessive movement may relay, trigger, or enable an override system to disable the lockout system, but keep the fuel flow isolation valve closed (safe state) and release the vehicle until appropriate control/conditions are obtained and/or present. Such a condition may stop or start any vehicle or automatic fuel fill release system that may exist or that may be initiated by a lockout. Variations of the steps and sequences may be used to maintain the security state. The vehicle may be allowed to move by automatically activating an override device if the isolation valve is in a closed position and if a predetermined condition exists.

For example, a natural gas-fueled barge may begin to slide away, or begin to roll and pitch beyond a certain limit. The motion sensor, together with the processing, may determine a course of action. If the movement is within a certain limit range, only the fuel filling system needs to be shut down; however, for greater movement or slipping away, it is necessary not only to shut down the fuel filling system, but also to automatically disconnect the fuel filling line from the barge.

Any type of fire or explosion during a refueling is also a danger signal that all refueling operations should be stopped. To detect a dangerous fire condition, the use of one or more sensors in combination with one or more microswitches may automatically close an isolation valve to prevent and/or disable fuel transfer and activate audible, visual and communication links such as fire alarms, pumps and fire suppression systems. Such sensors, such as optical or magnetic, may detect infrared, ultraviolet, thermal or temperature rise rates. Such a device may initiate a fire alarm or the like. Any flame/fire light scanner or laser sensor, fusible/frangible link, is within the scope of the invention. This includes any means of detecting a fire hazard. Fire protection systems typically require complex (multi-level or higher) resets, such as both keys and codes. The sensor may also be used in conjunction with standard fire detection systems as a control cascade.

To prevent further exacerbation of the fire or explosion hazard; an optional relay or digital or analog logic function activated by a fire detection system including one or more optical, magnetic, ultrasonic sensors or links in combination with one or more micro-switches, together provide and/or trigger/activate an override device, thus deactivating the locking system and releasing the vehicle when there is a fire or explosion risk. This enables the vehicle to move away from the source of fire or explosion, or to distance itself from further spread of the fire or explosion hazard, whether or not another refuelling vehicle is present, or refuelling is taking place from the storage container. Optical sensors such as infrared, ultraviolet, alone or in combination, can sense fire and/or heat; in addition, sensors such as temperature rise rate and ionization can detect excessive temperatures and smoke. The fusible/frangible link/and other sensors such as acoustic or ultrasonic sensor system receivers can detect large sudden noise/sound waves, such as those generated by rapid expansion or explosion of molecules in a confined environment. Any sensor activation also typically causes the system to begin closing the isolation valve and stopping/mitigating the fuel flow diversion; further, any vehicle or automatic fuel fill release system that may exist or that is initiated via a lockout is stopped or started.

All motion and fire/heat sensors are typically coupled to a processor. The processor executes the stored instructions from the memory and makes decisions to determine course of action using artificial intelligence techniques. As mentioned, this action may be a refueling shut-down only, or may be a complete disconnection of the fueling system from the vehicle. The sensors and/or processors may be part of the fueling supply system equipment, or they may be on the vehicle, or both.

The presence or absence of lng cold temperature is detected using an optical sensor such as an infrared temperature or fiber optic sensor, or differential temperature detection may determine the presence or absence in the fueling line and thus relay or digital or analog logic functions are deactivated together and vehicle lock is generated. These may also be flow switches or flow meters with conveyors. The sensor senses the presence of a natural gas filling hose proximate a tank filling adapter coupled to a natural gas tank.

The use of magnetic sensors such as "Mag meters", Coreolsis flow meters (U-tubes), densitometers (LVDTs/strain gauges) or mass flow (temperature/pressure compensated flow meters) and other methods of indicating flow are within the scope of the present invention. The sensor senses the presence of a natural gas filling hose proximate a tank filling adapter coupled to a natural gas tank. These sensors generate signals or relay digital or analog logic functions that together generate a vehicle lock signal.

It is also within the scope of the invention to use one or more ultrasonic sensors, such as flow meters, which may be of the external type clamped or monitored from outside the flow line, or which may measure flow internally within the line (submerged). Any other method of detection/proximity using ultrasonic, radar or other waves is also within the scope of the present invention. An ultrasonic sensor senses the presence of a natural gas filling hose proximate to a tank filling adapter coupled to a natural gas tank and senses or directs a manual and/or automatic refueling system to sense proximity, or whether a particular mechanical component is in a particular position; such as a hinged or extended fuel filler rack, tray, arm, hose line, or fuel filler and/or connector.

It is within the scope of the present invention to use an optical sensor, such as infrared, ultraviolet, laser optics, fiber optics, visible or invisible light, to detect the presence of a natural gas filling hose in proximity to a tank filling adapter coupled to a natural gas tank. These sensors can measure the interference of the optical beams, distance, obstructions, optical differences, presence, proximity, and whether the component is in a particular position. The optical sensor may have a transmitter that communicates wirelessly, such as by radio or optics. The sensor may sense proximity with a natural gas refueling hose leading a manual and/or automatic refueling system, or whether a particular mechanical component is in a particular location; such as a hinge or extension of a fuel filling stand, tray, arm, hose, line, hose line or fuel filling device and/or a connector.

Further, any standard temperature sensor, pressure sensor, or flow transmitter may be used to sense the presence of a natural gas refueling hose proximate to a tank refueling adapter coupled to a natural gas tank. All of the above sensors may have a transmitter that may communicate wirelessly, such as by optical or radio. The operator may perform different levels of reset to reset various system faults.

All of the above security systems, sensors, relays, triggers, microswitches, overrides, locks, resets and events should be continuously recorded and all the recorded logic data is Identified (ID) with the current time and date stamp and will be printed out when needed. The data records may be local or remote, or both. The data may be transmitted wirelessly to a remote location and, if desired, over a network such as the internet.

Turning to fig. 7, it can be seen that a fueling vehicle 200 is connected to a fueling system 201 by a fuel line 202, the fuel line 202 running through

isolation valves

203 and 204 on the system and vehicle, respectively. There is an automatic fuel line release 205 and an automatic vehicle release 211. Some vehicles, such as land vehicles, may not have an automatic vehicle release. However, both trains and ships are common. A processor 206 having a memory 207 executes the stored instructions. The processor 206 interfaces with fire and explosion sensors 209 and motion sensors 208. The processor executes artificial intelligence routines or other algorithms to determine when the vehicle is moving too much and whether a fire or explosion has occurred. If it is determined that there is too much movement, the

isolation valves

203 and 204 may be automatically closed. In more severe conditions such as extreme motion or roll-off motion, fuel line 202 may be released from the vehicle via fuel line release 205, and vehicle 200 may be released from the fueling system via vehicle release 211. In the case of a terrestrial vehicle, the vehicle locking device 210 may be overridden by the processor 206 so that the vehicle may be activated and/or moved. It should be understood that processor 206 may be in carrier 200, in a portion of fueling system 201, or split between the two as two separate processors. In view of the multitude of possible hazardous conditions or scenarios, the processor programming should be able to evaluate and take action on the conditions reported by many different sensors.

As noted above, the present invention relates generally to the field of vehicle safety and compression and liquefied gases, and more particularly to safety systems associated with natural gas powered vehicles that use multiple redundant systems and methods, such as spacecraft, launch rockets, and aircraft, to prevent an operator, pilot, or pilot from starting or moving a compressed gas vehicle with oxygen trim when the high pressure gas filling system is not properly and completely disconnected from the vehicle.

Today, a wide variety of inner and outer space trips are providing launch vehicles, spacecraft, rockets, subsonic and supersonic vehicles; some use rocket dual propellant engines, some use hybrid propulsion (natural gas turbine generators), some use turbofan, some use afterburner, and even ram-type engines for cargo transportation, satellite launch, exploration, probe car transportation, manned space (international space station), and faster, more efficient global transportation/travel. These vehicles (spacecraft/inner and outer space) that may be flying to multiple planets for various detection, observation, safety and transportation are now using natural gas (liquefied state) (LNG) or natural gas chemical families (such as ethane, propane, hydrogen, butane and other compounds) as fuel.

It is well known and understood that the natural gas composition varies from region to region, and that pure methane (also known as natural gas) is more severe to the scrubbing/refining/production process.

It is also well known in fire science that the combustion triangle requires three elements:

1) fuel 2) oxygen 3) ignition source

To obtain a proper specific impulse for natural gas fuel rocket propulsion; natural gas fuels must use oxidants, such as oxygen, either directly supplied or derived from oxygenates. The oxygen may also be compressed, washed, refrigerated and condensed into a liquid state to maximize storage space. Liquid Oxygen (LOX), vaporized to pure oxygen, may be mixed with the vaporized natural gas fuel. The oxygen-enriched fuel can be used for producing clean, green and excellent propellants for rockets, spacecraft and aircrafts.

Liquefied Natural Gas (LNG) has several advantages for these modern vehicles:

1) liquefied natural gas is denser than other existing fuels; therefore, the fuel tank size is reduced.

2) The temperature of the liquefied natural gas is very close to that of the liquefied oxygen, simplifying storage, which is a major engineering obstacle.

3) Natural gas turbine! The sealing element of the turbopump driven by the internal combustion engine only needs to have a narrow temperature band, so that the temperature difference problem is reduced.

4) Due to the high vapor pressure of lng, gas starvation is not required.

5) The natural gas evaporates less spatially, thereby improving efficiency.

6) Natural gas and oxygen have a positive chemical affinity.

7) Natural gas is green and environmentally friendly and is non-toxic compared to other fuels.

8) Methane is most likely obtained on mars, saturn, mars and other planets; return fuel is provided for the teams.

There are various recipes, models and propellant spacecraft/vehicles in common development, each entity having various commitments, but all with the same goals: safe and efficient spacecraft/vehicles. Natural gas and oxygen can be safely handled using existing best technologies. An intelligent system using sensors that are safe in principle can mitigate risks during oxygen or fuel enrichment and natural gas fuel itself fueling and filling.

Appropriate atmosphere monitoring systems and controls may mitigate the risk of detonation and explosion during refueling, or whenever fuel and/or oxygen is present. Monitoring the atmosphere for both CH4 and 02 (starvation and enrichment) is absolutely safe. Optical sensors such as fiber optic sensors having both closed cells and open pathways may be used with electrochemical detection. The sensors may communicate wirelessly, by radio or optically, with one or more central or remote systems. The analyzer may also be used to perform atmosphere monitoring. Systems such as the Ramen spectroscopy method are within the scope of the present invention.

Natural gas in air has a Lower Explosion Limit (LEL) of 5%; and the Upper Explosion Limit (UEL) is 15%. However, when pure oxygen is present, the LEL remains at about 5%, while the upper explosive limit increases to 59% to 61% (depending on the natural gas composition). With the introduction of pure oxygen, the risk of the atmosphere will increase by several orders of magnitude, since oxygen also reduces the ignition temperature and the energy required for ignition. Leakage of fuel, oxygen, or both will enrich the surrounding atmosphere with potentially catastrophic consequences. Minimal sparking, arcing, rapid pressurization, acoustic resonance, friction, or even spontaneous combustion can momentarily ignite the now flammable/highly flammable and explosive mixture into a runaway exothermic reaction, or the rapid expansion of molecules in confined or unrestricted spaces. Fiber optic sensors used for oxygen detection alone or in combination with spectrometers can detect oxygen levels from 0% to 100%. For methane, the explosion limit range for an optical/fiber optic sensor alone or in combination with a spectrometer will detect l.e.l. is 0% to 100%. A preferred approach is to combine these two types of sensors into a single analyzer to handle different l.e.l. ranges corresponding to different oxygen levels.

It is critical that the fuel and oxidant be contained safely at all times, but this is critical during refueling. One or more microswitches, which may be optical, magnetic or ultrasonic, are combined with one or more sensors to prevent ignition or removal of the mobile safety vehicle from/locking within the scope of the present invention. For different safety levels, different combinations of sensors may be used, with the lowest level having a single proximity sensor that senses the presence or absence of a high pressure fill hose. The highest level of safety is achieved by having separate proximity sensors on the fuel and oxygen fill hose fittings, the air cap cover, and the manual or automatic safety valve with redundant microswitches. An optional override, which may limit the number of times it can be used, may allow for the start of a failed sensor to allow for maintenance. The system should be active during both the test stand launch and the actual launch or takeoff/lift-off. Some countries have established "no-fly zones" around LNG facilities.

To detect omnidirectional vehicle/space/aircraft movement/distance, multiple sensors may perform different functions individually, or vehicle/space/aircraft "lock" in a cascaded/sub-programmed control system. The use of one or more sensors in combination with one or more micro-switches or other switches automatically determines when a threshold limit is exceeded and may initiate a "lockout" of the fuel fill system that closes one or more isolation valves to prevent/disable fuel/oxidant flow/transfer. Sensors such as optical, magnetic, ultrasonic, accelerometer, etc. can detect any or excessive movement of the carrier (above or above a predetermined limit). One or more sensors, or a combination of all of these sensors, can monitor and control fuel and oxidant flow and immediately switch the system to a "lock-out" state and activate one or more visual and/or audible alarms. Typically, the operator can restart the fuel/oxidant flow when safety conditions are warranted.

Different vehicles may require different types of control. For example, excessive movement may relay, trigger, or enable an "override" system, thereby disabling a "lockout" system, but keeping the fuel flow isolation valve closed (safe state) and releasing one or more vehicles until proper control and conditions are reached. Furthermore, it may stop or start any vehicle or automatic fuel fill release system that may exist or that may be initiated by a lock. Variations may be used with steps and sequences to maintain the "safe state" of the isolation valve in the closed position, and if predetermined safety conditions exist, the vehicle may be allowed to move by automatically initiating an "override".

To detect a dangerous fire condition, one or more sensors are used in combination with one or more micro-switches to automatically close one or more isolation valves to prevent and/or disable fuel flow! Divert and activate the audio, visual, communication link, fire alarm, pump, and fire suppression systems. Sensors such as optical or magnetic may detect infrared, ultraviolet or temperature rise rates. These devices may activate a fire alarm and may also include any other fire/flame scanner/laser optical sensors and fusible/frangible links. Any device, sensor, or technique for detecting a fire hazard is within the scope of the present invention, including but not limited to complex (multi-level or higher) resets required for fire protection systems, such as keys and codes.

To prevent further exacerbation of the fire or explosion hazard; optional relays or digital or analog logic functions activated by a fire detection system including one or more optical, magnetic, ultrasonic sensors or links may be combined with one or more micro-switches to provide locking or override locking. When a fire or explosion hazard exists, the override device releases the carrier, enabling the carrier to be located away from the source of the fire or explosion, or to itself be located a distance away, so as not to further spread the fire or explosion hazard.

Optical sensors such as infrared and ultraviolet may sense fire and/or heat, either alone or in combination. In addition, sensors such as rate of rise and ionization can detect excessive temperatures and smoke. Fusible/frangible link! And other sensors such as acoustic or ultrasonic sensor system receivers can detect large sudden noise/sound waves such as those generated by rapid expansion or explosion of molecules in a confined environment. Any sensor activation may also cause the system to begin closing one or more isolation valves and stop/mitigate fuel flow diversion; further, any vehicle or automatic fuel fill release system that may exist or that has been initiated by a lockout is stopped or started.

The presence or absence in the LNG refueling line may be determined using an optical sensor, such as an infrared temperature sensor or a fiber optic sensor, to detect the presence or absence of liquefied natural gas/oxygen, cryogenic temperature, or temperature differential. Thus, relays or digital or analog logic functions may be combined to deactivate and generate a vehicle "lock. This may also include a flow switch or meter with a feeder. The one or more sensors may also sense the presence of a natural gas/oxygen fill hose proximate a tank fill adapter coupled to the natural gas/oxygen tank.

The use of magnetic sensors such as "Mag meters", Coreolsis flow meters (U-tubes), densitometers (LVDTs/strain gauges) or mass flow (temperature/pressure compensated flow meters) and other methods of indicating flow are within the scope of the present invention.

Ultrasonic sensors may also be used, such as a flow meter that may be of the external type that is clamped or monitored from outside the flow line, or that may measure flow internally within the line (submerged). Other methods of detection/proximity using ultrasonic, radar or other sound waves are also within the scope of the present invention. These ultrasonic sensors sense the presence of a natural gas/oxygen fill hose in proximity to a tank fill adapter coupled to a natural gas/oxygen tank and sense or direct a manual and/or automatic refueling system to sense proximity, or whether a particular mechanical component is in a particular location. This may be a hinging or extension of the refueling stand, tray, arm, hose/line or refueling apparatus and/or connection/connector.

Optical sensors such as infrared, ultraviolet, laser, fiber optic, visible or invisible light may also be used to detect the presence of a natural gas/oxygen fill hose in proximity to a tank fill adapter coupled to a natural gas/oxygen tank. These sensors may measure interference of light beams, distance, obstacles, light differences, presence of components, proximity, or whether components are in a particular location. Any sensor may have one or more wireless communicating transmitters/transceivers, such as by wireless radio or optical wireless communication. These sensors may also sense proximity with a natural gas refueling hose guided manual and/or automatic refueling systems, or whether a particular mechanical component is in a particular location; such as a hinge or extension of a fuel filling stand, tray, arm, hose, line, hose line or fuel filling device and/or a connector.

All of the above security systems, sensors, relays, triggers, microswitches, overrides, locks, resets and events can be continuously monitored, recorded, and all recorded data can be identified with a unique ID associated with position and part number, and a current time and date stamp. All recorded data can be printed out on demand.

Fig. 8 shows an example of an LNG/LOX fueling safety system in accordance with an embodiment of the present invention. A rocket, aircraft or other vehicle 300 being fueled is connected to a fueling system 310 via LNG fuel line 303 and LOX oxidizer line 304. The fuel fill system 310 has a safety lockout device 311, which safety lockout device 311 can stop fueling very quickly (on the order of milliseconds or faster). The processor 301 or other logic in combination with the memory 302 acts as a logic circuit. The processor is coupled to a fire/explosion sensor 306, an LNG presence sensor 305, and LOX oxygen above ambient concentration sensor 308. Processor 301 is also coupled to LNG hose proximity detector 307 and LOX hose proximity sensor 309. The processor 301 or logic circuitry immediately (in microseconds) sends a command to the fuel fill system lockout device 311 to stop fueling upon sensing a hazardous condition from any of the coupled sensors. A quick shut-off valve in the fueling system 310 may mechanically shut off fueling flow as quickly as possible. Many other sensors and sensor types previously discussed may be incorporated into this system as desired. These may include motion detectors and detectors on the isolation valve.

Several descriptions and illustrations have been presented to aid in understanding the nature of the invention. It will be apparent to those skilled in the art that many changes and modifications can be made without departing from the spirit of the invention. Each of these variations and modifications is within the scope of the present invention.

Claims

1. A vehicle safety system for deactivating a natural gas-fueled vehicle when fueled from a natural gas fueling system, comprising:

a first sensor adapted to sense the presence of a gas filling hose proximate a canister filling adapter coupled to a source of pressurized gas;

a second sensor adapted to sense an open/closed position of an isolation valve that, when closed, isolates the canister priming adapter from the source of pressurized gas;

logic circuitry adapted to combine inputs from the first and second sensors to generate a safety electrical signal indicative of a safety condition when the gas filling hose is not proximate to the canister filling adapter and the isolation valve is closed;

a lock-out circuit adapted to disable the vehicle when the safety electrical signal is not present;

a plurality of motion sensors configured to detect excessive movement of the vehicle, a first sensor of the plurality of motion sensors configured to detect roll off of the vehicle, a second sensor of the plurality of motion sensors configured to detect roll or tilt of the vehicle;

wherein the first and second ones of the plurality of motion sensors are coupled to: a processor, a cascade control circuit, the logic circuit, or a relay configured to: shutting down the natural gas fueling system after the vehicle slips off or shakes or tilts beyond a first predetermined limit, and shutting down the natural gas fueling system after the vehicle slips off or shakes or tilts beyond a second predetermined limit, the second predetermined limit being greater than the first predetermined limit.

2. The vehicle security system of claim 1, wherein the locking circuit is further configured to override an active locking device such that the vehicle is movable.

3. An aircraft fueling safety system for a vehicle that uses Liquefied Natural Gas (LNG) fuel and an oxidizer other than air, comprising:

a fueling system, including LNG fuel and a liquid or solid oxidizer other than air, configured to fuel the aircraft;

a first sensor configured to detect the presence of LNG, the first sensor located proximate to the fueling system;

a second sensor configured to detect an oxygen concentration that is a predetermined amount above an ambient air concentration, the second sensor located proximate to the fuel fill system;

a third sensor configured to detect a fire or explosion;

a fourth sensor configured to detect proximity of an LNG hose to an LNG coupler on the aircraft;

a fifth sensor configured to detect proximity of a Liquid Oxygen (LOX) hose to a LOX coupler on the aircraft;

a logic system that combines inputs from the first sensor, the second sensor, the third sensor, the fourth sensor, and the fifth sensor such that the fueling system is placed in a locked state after LNG is detected by the first sensor, or after oxygen above ambient concentration by the predetermined amount is detected by the second sensor, or after a fire or explosion is detected by the third sensor, or after LNG hose is detected by the fourth sensor as not being proximate to the LNG coupler, or after LOX hose is detected by the fifth sensor as not being proximate to the LOX coupler;

a manual override system configured to remove and deactivate the locked state.

4. The fueling safety system of claim 3, wherein the third sensor is a fire or explosion sensor selected from the group consisting of optical and ultrasonic.

5. The refueling safety system of claim 4, wherein the fire or explosion sensor is an infrared sensor.

6. The fuel fill safety system of claim 3, wherein the first sensor is selected from the group consisting of an optical sensor and a chemical detector.

7. The fuel fill safety system of claim 3, wherein the second sensor is a chemical detector.

8. The fuel filling safety system of claim 3, wherein the aircraft comprises a rocket.

9. An aircraft fueling safety system for a vehicle using Liquefied Natural Gas (LNG) fuel and Liquid Oxygen (LOX), comprising:

a first sensor configured to detect the presence of LNG, the first sensor configured to be located proximate to a fueling system;

a second sensor configured to detect an oxygen concentration that is a predetermined amount above an ambient air concentration, the second sensor configured to be located proximate to the fuel fill system;

a third sensor configured to detect a fire or explosion;

a fifth sensor configured to detect proximity of a LOX hose to a LOX coupler on the aircraft;

a logic system that combines inputs from the first sensor, the second sensor, the third sensor, the fourth sensor, and the fifth sensor such that the fueling system is placed in a locked state after LNG is detected by the first sensor, or after oxygen above ambient concentration by the predetermined amount is detected by the second sensor, or after a fire or explosion is detected by the third sensor, or after LNG hose is detected by the fourth sensor as not being proximate to the LNG coupler, or after LOX hose is detected by the fifth sensor as not being proximate to the LOX coupler.

10. The fueling safety system of claim 9, wherein the third sensor is a fire or explosion sensor selected from the group consisting of optical and ultrasonic.

11. The fuel fill safety system of claim 9, wherein the first sensor is selected from the group consisting of an optical sensor and a chemical detector.

12. The fuel fill safety system of claim 9, wherein the second sensor is a chemical detector.

13. The fuel fill safety system of claim 9, further comprising a motion sensor coupled to the logic system, wherein the logic system is configured to place the fuel fill system in a locked state after detecting movement of the aircraft above a predetermined amount.

14. The fuel filling safety system of claim 9, wherein the aircraft comprises a rocket.