RS20170683A1 - Mobile gas fuelling station - Google Patents

Description

MOBILE GAS SUPPLY STATION

TECHNICAL FIELD

This invention has realized a simple, inexpensive, reliable process and construction solution for the distribution of combustible gases (natural gas, hydrogen, etc.) from compressed gas transport tanks (trucks, trailers, semi-trailers, trains, ships and other vehicles) to consumer tanks (tanks on NGV vehicles, stationary consumer tanks, etc.) that require a high final gas pressure, which is comparable to the gas pressure in road tanks, in order to ensure a large amount of stored gas. The present invention enables gas-powered motor vehicle and stationary storage tanks to be refilled quickly and efficiently over a wide range of intake pressures (ie, varying gas pressure within the gas transfer tank).

STATE OF THE ART

Transporting natural gas without pipelines in compressed form (CNG) using transport vehicles (trailers, semi-trailers, trucks, railway trains, ships) is becoming increasingly popular in areas where there are no regular gas pipelines.

In principle, there are two distinctive applications for pipelineless CNG transport and supply: one is for industrial, commercial and residential direct gas use by transferring gas from a high-pressure mobile carrier to low-pressure consumer devices (burners, etc.); the second is the transfer of gas from one (or more) high-pressure tanks to another high-pressure tank(s), for example, in the case of natural gas vehicles (NGV), when the gas is delivered from another gas carrier to the tank on the vehicle.

In the latter case, we face the problem of filling the tank on the NGV vehicle under high pressure (usually 200-250 bar), because in the gas carriers the gas is also stored under a pressure of 200-250 bar. The gas that is compressed under high pressure in the carrier tanks starts to lose pressure as soon as it passes through the outlet valve and enters the high pressure line leading to the next tank (on-board tank for NGV or stationary tank of any consumer). Without recompression or any other procedure to maintain the gas pressure in the gas transfer tank, the transfer of gas from one vessel to another vessel results in the equalization of the pressures between the two aforementioned vessels. In order to directly connect the two, the transmission tanks and the consumer tanks, the consumer gas tanks cannot be filled to the maximum required pressure. Now, to overcome the above problem of gas pressure drop in consumer tanks, which are refilled from mobile compressed gas stations, mechanical and/or hydraulic compressors are used at the consumer or at the mobile charging station on the vehicle.

In this case, the problem is as follows. Conventional reciprocating compressors cannot operate over the wide range of inlet pressures (such as about 10-250 bar) generally required for mobile gas compression in mobile gas supply systems. Inlet pressures for common compressors are generally limited to narrow ranges, which are based on the operating pressures of the equipment and the ratio of outlet pressure to inlet pressure for each stage (typically a ratio of 3 - 4 for each stage is the maximum operating ratio for common compressors). In addition, conventional compressors usually have a low possible maximum inlet pressure (such as 20-30 bar) due to the pressure limitations of the compressor casing and shaft seals. The above limitation, which is inherent in conventional compressors, limits the applicability of these compressors for mobile gas supply. Compressors that provide a wide range of suction pressures (10-250 bar) are very bulky and expensive.

Other previously described CNG refueling systems use cylinders filled with adsorbent to reduce the pressure in the tank required to store a predetermined amount of natural gas. Such systems are described, for example, in US Pat. no.

4,522,159; 4,531,558; and 4,749,384.

However, currently only a few companies offer HPU on the market, where all proposed systems can only be applied on pipe transport trailers, which are supplied with only 4-12 gas pipes, while most of the existing mobile supply stations (based mainly on trucks, trailers and semi-trailers) are equipped with a large number of relatively small cylindrical tanks (150 - 300 cylinders). Among these companies are NEOgas (USA), ENK (Korea), Enric (China).

In addition to the possibility of being used only in pipe transport trailers, existing HPUs have the following disadvantages:

- a large volume of hydraulic fluid is required from a large hydraulic fluid reservoir (for example, in the ENK system 5000 1, in the Neo Gas system about 3000 1). A large amount of hydraulic fluid requires considerable power to handle; in colder climates it must be preheated, etc.

- once the vessels are filled with hydraulic fluid, a considerable period of time is required to empty the vessels

THE ESSENCE OF THE DESCRIBED TECHNOLOGY

The first four examples of the implementation of the proposed mobile charging station are shown in Figure 1.

In all cases, the system contains the following elements:

1) a truck or a combination of vehicles that is a tractor - semi-trailer, or a tractor - trailer.

2) a common device (2) for power take off (eng. power take off, abbreviated PTO) from a vehicle (tractor) which is connected to the tractor or truck transmission, which contains a secondary drive shaft and another control system for switching on and off the power take off.

3) air driven gas booster.

3) source of compressed air.

BRIEF DESCRIPTION OF THE DRAFT PICTURES

Figure 1 is a schematic view of a mobile gas supply station based on air-driven booster-compressors. This figure shows a found system according to the first four system embodiments, that is, a system comprising an air compressor on a vehicle or trailer or a stationary compressor or an on-board air accumulator/stationary air accumulator. 1) - version with mechanical PTO on the vehicle, 2) version with mobile compressor, 3) version with external stationary compressor, 4) version with air accumulators; A - on-board storage cylinders, B - on-board charging cylinders, BR - air-powered booster; * air circuit, ────── gas circuit. ;(a), (b), (s), (d), (e), (f), (g), (h), (i) - lines I, II, III, IV, V, VI, VII, VIII, IX, X - for gas, shut-off valves ;1 - tractor engine, 2 - power take-off, 3 - compressor driven by PTO on the vehicle, 4 - air choke tank, 5 - mobile compressor driven by internal combustion engine or electric motor, 6 - stationary compressor driven by an internal combustion engine or electric motor, 7 - high-pressure air tanks - accumulators, 8 - consumer gas tank (on the vehicle or stationary), 9 - stationary gas filling station, 10 - quick coupling, 11 - gas supply pipeline, 12 - pressure regulator. ;;Figure 2 is a schematic layout of a mobile gas supply station based on air-driven booster-compressors. This figure shows the system found according to the fifth and sixth embodiments. A fifth exemplary embodiment is a system comprising two gas boosters, the first operating in the high-pressure gas suction zone, while the second operates in the low-pressure gas suction zone. The sixth embodiment is a system where instead of a direct mechanical drive from the PTO, a hydraulic or electric drive is used to ensure the operation of the compressor on the vehicle. ;; ;; BR 1 - air-driven booster under BR 2 - air-driven high-low-pressure booster; 1 - tractor engine, 2 - hydraulic pump or generator driven by power take-off, 3 - hydraulic or electric motor, 4 - gas booster, 5 - air choke tank, 6 - gas consumer tank, 7 - pressure regulator, 8 - stationary gas filling station, 9 - quick coupling. ;;Figure 3 is a schematic layout of a mobile gas supply station based on air-driven booster-compressors. This figure shows the found system according to the seventh embodiment where any vehicle equipped with a compressor or accumulator for compressed air is independently supplied with gas from a gas transport tank or any stationary gas storage tank. ;I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII - shut-off valves ;(a), (b), (c), (d), (e), (f), (gl), (g2), (h), (i) - gas lines A - cylinders ;for on-board storage, B - on-board charging cylinders, ;BR - air-powered booster ;1 - tractor engine, 2 - power take-off, 3 - compressor driven by the PTO on the vehicle, 4 - accumulator for compressed gas, 5 - cylinders for gas supply on the vehicle, 6 - gas consumer tank, 7 - stationary charging station, 8 - quick coupling, 9 - pressure regulator ;;DETAILED DESCRIPTION OF THE INVENTION ;;Depending on the compressed air source, our invention has four examples of implementation, In the first example of implementation, the air source is a mechanical compressor (3) for air that is driven by the PTO. In another exemplary embodiment, the air source is a mobile compressor powered by any SUS (internal combustion engine) or electric motor powered from the mains or by a generator. In the third embodiment, the supply of compressed air is provided by any stationary compressor driven by any SUS (internal combustion engine) or electric motor powered from the network or by a generator. In the fourth embodiment, the cylinder accumulator for high-pressure air serves as a source of compressed air. ;;4) The air driven gas booster is connected to the air source. It is a good alternative to stationary type high pressure compressors. These boosters have a compact and light weight construction. ;;Buster has two sections. The first - for compressed air, into which air is supplied under a pressure of 6-10 bar from any air source, and after the work cycle it is released into the atmosphere under a pressure of close to one bar. The second - for compressed gas, in which the gas is sucked in under any pressure, then compressed to the desired pressure and supplied to the consumer. ;;5) Two groups of high pressure cylinders (A, B), which are mounted on the deck or chassis of the truck or semi-trailer/trailer. ;;6) Piping, valves, instrumentation ;The associated components are: a gas supply station (9) placed near the gas pipeline and a tank (8) of the consumer for gas storage. ;;Although the consumer gas storage tank (8), the BR gas-compressor booster, the throttle tank (4), the compressed air-accumulator tank (7) are shown in Figure 1 as individual components, it is obvious to those skilled in the art that, after reading this description, they can be replaced by a multitude of interconnected components. ;;All sources of compressed air are designed and constructed so that they work under operating air pressures in the range of 6-12 bar and with gas inlet pressure in the range of about 10-200/250 bar (depending on the country). The maximum outlet pressure is 250 - 300 bar. ;;These data correspond to Europe (200 bar) and the USA, since the working pressure in the CNG system of 250 bar is accepted in the USA. Of course, it is possible to connect two or more air sources in parallel, when it is necessary to achieve an increased possibility of recharging or the possibility that one source may be switched off over time for maintenance or repair. ;;A semi-trailer or trailer or truck or any other vehicle (ship, railway wagon, etc.) carries a group of cylinders which includes supply cylinders (group A) and charging cylinders (group B). Supply cylinders (A) have only one inlet/outlet port, while charging cylinders are provided with two ports on both sides. The upper side of the cylinders (A) is alternatively connected to the suction line (d) of the booster by the supply line (cl) from the gas supply station. The upper side of the filling cylinders (B) is alternatively connected to the supply water (b) from the gas supply station and suction water (c2) of the booster. ;;The system according to the first four implementation examples works in seven operating modes as follows. ;;First operating mode: The empty mobile filling station comes to the stationary gas station (9) and is connected to the outlet line from the gas compressor by means of a quick coupling 10. All cylinders on the vehicle are filled from the stationary gas supply station (9). During this time, valves II, III, VIII are open (all other valves are closed) and gas flows through pipes (a), (b) and (c) to the cylinders of both groups A and B. When the preset pressure in the cylinders is reached, then valves II and III are closed, and the mobile station moves to the area of the first consumer. ;If the invention is implemented in the US market, then the tanks are filled to a pressure of 250 bar (3625 psi) or 310 bar (4500 psi) at standard temperature. In accordance with the NGV-2 Standard, set by the Natural Gas Vehicle Coalition, CNG tanks can be overfilled by 25% of their nominal capacity, or nominal pressure. Accordingly, in Europe the max. tank pressure 200 bar (3000 psig) or the tank can be filled to 259 bar (3750 psig). ;;Second operating mode: BR boosters pump gas from groups of cylinders A and B simultaneously to the tank (8) of the consumer. During this time, valves II, III, VI, VII, IX are open, while all other valves are closed. Gas flows from groups of cylinders A and B through pipes (b), (cl), (d), (e), (f), (g) and the pressure regulator (12) to the tank (8). ;;Third operating mode: Boosters BR pump gas from cylinder group B to the tank (8) of the consumer. During this time, valves I, III, VII, IX are open, and booster BR takes gas from cylinder group B and delivers it to the tank (8) of the consumer through pipes (c2), (d), (e), (f), (g). ;;Fourth operating mode: Buster BR pumps gas from cylinder group A to cylinder group B. During this time, valves V, III, VI, IX are open, and buster BR pumps gas from cylinder group A through pipes (cl), (d) and (h) to cylinder group B. ;;Fifth operating mode: Decanting from both cylinder groups A and B. During this time, valves II, II, IV are open, and gas flows from cylinder groups A and B through pipes (cl), (b), (i), (g) to the tank (8) of the consumer. ;;Sixth operating mode: Decanting gas from cylinder group B. During this time, valves IV, III are open, and gas flows from cylinder group B through pipes (b), (i), (g) to the tank (8) of the consumer. ;;Seventh operating mode: The system is used as a stationary compressed gas station, and the gas is pumped directly from the pipeline or gas storage tank to the consumer tank bypassing the vehicle's gas storage cylinders A and B. During this time, valves III, VII, IX, X, XI are open and gas flows from pipeline 11 through pipes (a) and (sZ) to the booster BR and from the booster through pipes (e), (f), (g) to the tank (8) of the consumer. ;The above operating modes are applied alternatively to achieve an effective working algorithm of the system in question depending on the characteristics of the boosters used, the type of consumer (NGV or stationary consumer devices), the phase of the work cycle (moving on the road, emptying), the emptying phase (initial phase with the pressure in the tanker tank close to the maximum or minimum, etc.). For example, the fourth operating mode can be applied during the movement of the tanker from one consumer to another or in the case when the booster works effectively under a relatively high suction pressure, etc. ;;The fifth and sixth examples of execution are shown in Figure 2. ;The fifth example of execution differs from the first four examples of execution by the application of two boosters: the first booster works in the gas suction zone under high pressure; while the second booster works in the low-pressure gas suction zone. Such a construction enables achieving the desired constant capacity in a wide range of gas suction under pressure. ;;The system works in the seventh operating mode as follows. ;;First operating mode: Cylinders on the vehicle are filled from a stationary gas supply station. ;;Second operating mode: Both boosters BR1 and BR2 pump gas from cylinder groups A and B simultaneously to the tank (6) of the consumer. The mode of operation is similar to the first four examples, and valve IX is open. ;;Third operating mode: Both boosters BR1 and BR2 pump gas from cylinder groups A to cylinder groups B. The mode of operation is similar to the first four execution examples, and valve IX is open. Fourth operating mode: Buster BRl pumps gas from cylinder group A to cylinder group B, while booster BR2 supplies the tank (5) of consumers from cylinder group B. During this time, valves V, VI, VIII, X are open, while booster BRl pumps gas from cylinder group A through pipes (cl), (dl) and (h) to cylinder group B. During this time, valves I, VII and XI are open, while booster BR2 takes gas from cylinder group B and delivers gas to the tank 5 consumers through pipes (e2), (f), (g). Accordingly, the booster BRl accepts the high pressure input due to the gas pumped from the inlet, or supply line using booster BR2. ;Fifth operating mode: Buster BRl pumps gas from both groups of cylinders A and B to the consumer tank. During this time, valves II, VI, VII, VIII, XII are open, and gas flows through pipes (c), (dl), (el), (f), (g) from both groups of cylinders to the tank (6) of the consumer. ;;Sixth operating mode: Decanting from both groups of cylinders A and B. During this time, valves II, IV, VIII are open, and gas flows from the group of cylinders A and B through pipes (b), (i), (g) to the tank (8) of the consumer. ;;Seventh operating mode: Decanting from cylinder groups B. During this time, valves IV, VIII are open, and gas flows from cylinder group B through pipes (b), (i), (g) to the consumer tank (8). This provides many possibilities for the application of different algorithms depending on the parameters of the booster and the charging capacity (NGV, stationary consumer devices, etc.). ;;In the sixth embodiment, a hydraulic or electric drive is used instead of a direct mechanical drive (to provide air for the compressor on the vehicle). In this case, it is possible to use remote power supply and install the booster at any remote location. The hydraulic motor or generator (2) is driven directly by the PTO, while the hydraulic or electric motor (3) is mounted on the remote air compressor (4). ;;The seventh embodiment is shown in Figure 3. According to this embodiment, any vehicle equipped with a compressor or accumulator for compressed air can only be filled with gas from a gas transport tank equipped with gas tanks and a gas booster, or together with this, fill any other stationary consumer or NGV. ;;The system contains the following elements: ;;1) A gas transport tank which is a truck or vehicle combination which is a tractor-semi-trailer, or tractor-trailer equipped with an air-driven gas booster) and gas storage cylinders mounted on the deck or chassis of the gas transport tank ;;2) NGV equipped with a PTO-driven air compressor. ;4) The usual mechanical, hydraulic or electrical device of the vehicle for power take-off (eng. Power Take Off, abbreviated PTO) or the accumulator for compressed gas on the vehicle or the external accumulator for compressed gas;;; 5) Tank(s) on the vehicle for filling with gas. ;;6) Piping, valves, instrumentation ;;Associated components are: a gas filling point connected to a gas main or distribution pipeline or an external gas storage tank. ;;The system works by analogy with the previous performance example for all the above-mentioned operating modes. ;; *

Claims (14)

PATENT REQUESTS 1. A mobile gas supply station containing: a cargo vehicle (wheeled truck, tracked vehicle, railway wagon, ship, etc.) or semi-trailer tractor (wheeled or tracked tractor with trailer, semi-trailer, barge pusher, etc.), multiple high-pressure gas storage vessels forming two circuits that specifically contain gas storage vessels and gas filling vessels, an air-driven gas booster having a section for gas connected to the above circuits and a source of compressed air. 2. A mobile gas supply station, in which high-pressure vessels are carried within each circuit and connected to each other by a common pipeline, and these circuits are interconnected, and are also connected to the suction and discharge section of the booster and the water for pushing the gas of the compressor at the stationary gas supply station or stationary gas storage tank. 3. The method of claim 1, wherein the dual circuit court system operates in seven operating modes including the following: 1) Vessels in both circuits are filled simultaneously from a stationary gas supply station or an external gas storage tank, 2) Gas boosters pump gas simultaneously from groups of cylinders belonging to both cars to the consumer tank, 3) Gas boosters pump gas from a group of cylinders belonging to the supply circuit to the consumer tank, 4) Buster pumps gas from the group of cylinders belonging to the storage circuit to the group of cylinders belonging to the supply circuit, 5) Gas simultaneously flows by decanting from a group of cylinders that belong to both the storage circuit and the supply circuit, 6) Gas flows by decanting from a group of cylinders belonging to the supply circuit, 7) The system is used as a stationary station for compressed gas and the gas is pumped directly from the gas pipeline or gas storage tank to the consumer tank bypassing the gas cylinders on the vehicle belonging to both the storage circuit and the supply circuit. 4. A mobile gas supply station according to claim 1, wherein two interconnected gas boosters are used, wherein the gas inlet section of the low pressure booster is connected to both circuits alternatively or together and the outlet pressure section of the low pressure booster is connected to the consumer tank and the supply circuit, while the outlet section of the high pressure booster is connected only to the consumer tank. 5. The method according to claim 4, wherein the boosters work in seven operating modes: First operating mode: On-board cylinders belonging to both cars are filled simultaneously from a stationary gas supply station. Second operating mode: Both boosters together pump gas from a group of cylinders belonging to both cars simultaneously to the consumer's tank. Third operating mode: Both boosters together pump gas from the group of cylinders belonging to the storage circuit to the group of cylinders belonging to the charging circuit. Fourth operating mode: The low-pressure booster pumps gas from the cylinder groups belonging to the storage circuit to the cylinder group belonging to the supply circuit, while the high-pressure booster pumps gas from the cylinder group belonging to the supply circuit to the consumer tank. Fifth operating mode: The low-pressure booster pumps gas from groups of cylinders belonging to both cars to the consumer tank. Fifth operating mode: The low-pressure booster pumps gas from groups of cylinders belonging to both cars to the consumer tank. Sixth operating mode: Gas flows by decantation from groups of cylinders belonging to both circuits to the consumer tank Seventh operating mode: Gas flows by decanting from a group of cylinders belonging to the supply circuit to the consumer tank. 6. The mobile gas supply station of claim 1, wherein the compressed gas source is an on-board air compressor powered by any PTO. 7. Mobile gas supply station according to claim 1, wherein the source of compressed gas is an air compressor on a trailer driven by an internal combustion engine or an electric motor. 8. Mobile gas supply station according to claim 1, wherein the compressed gas source is a stationary external air compressor driven by an internal combustion engine or an electric motor. 9. A mobile gas supply station according to claim 1, wherein the compressed gas source is a stationary external compressed air accumulator(s) or an on-board accumulator(s). 10. Mobile gas supply station according to claim 6, wherein the drive system from the PTO to the compressor is mechanical. 11 The mobile gas supply station according to claim 6, wherein the drive system from the PTO to the compressor is a hydraulic system comprising a hydraulic pump driven by a PTO and a hydraulic motor. 12. The mobile gas supply station according to claim 6, wherein the drive system from the PTO to the compressor is an electrical system comprising a generator driven by the PTO and an electric motor. 13. The mobile gas supply station according to claim 12, contains a backup system that represents power from the network for the electric motor. 14. The method according to claim 4, wherein the vehicle performs its own filling from a gas transport tank or an external gas storage tank under low pressure or a main or distribution gas pipeline.