TW201727134A - Filling station having a constant-pressure store - Google Patents

Abstract

The invention relates to a filling station and to a method for filling reservoirs in mobile vehicles (33) at a filling station, wherein the gas is stored in one or more constant-pressure stores (25) and is dispensed by means of a gas-conditioning unit (24) and a dispenser (30) in a withdrawal phase. The pressure is held constant in the one or more constant-pressure stores (25) during a withdrawal phase in that a liquid is conveyed from a liquid store (26) into the one or more constant-pressure stores (25).

Description

Gas station with constant pressure storage

The present invention relates to a gas station whose task is to load a gas into a storage container provided on a mobile vehicle, and further to a method of loading a gas at a gas station to a storage container on a mobile vehicle.

Gaseous materials, such as hydrogen or natural gas, are increasingly used as fuels for automobiles, such as in internal combustion engines or fuel cells. There are currently gas stations designed to fill vehicles with gaseous or liquid fuels such as hydrogen or natural gas, especially for cars, buses, locomotives, trucks, or forklift trucks. Since vehicles that use gaseous substances as fuel, especially those that use hydrogen as fuel, are not yet widely available in the market, the investment cost of such gas stations is very high. Traditional types of gas stations require a lot of facilities, which means high investment and maintenance costs (see Figure 1). These facilities typically include a gas storage vessel divided into a plurality of pressure levels, a compressor, an air compressor, a pump, and a storage control unit. The cost of these facilities, coupled with the low frequency of use of gas stations, especially hydrogen stations, makes gas stations difficult to profit. But the fewer the number of such stations, the harder it is to market in hydrogen-fueled vehicles. Although gas stations that load natural gas for vehicles have appeared many years ago, This type of gas station stores natural gas at a low pressure of 100 to 300 bar. Modern vehicles, however, are equipped with reservoirs that store hydrogen at very high pressures. The advantage of being equipped with this type of storage is that it can increase the distance traveled by the vehicle. Due to the material nature of hydrogen, facilities for gas stations handling hydrogen must meet more requirements than gas stations that process natural gas to ensure that the gas station meets the necessary safety and long service life.

The object of the present invention is to propose a gas station whose task is to load a gas, in particular hydrogen, into a storage container provided in the vehicle, and such a gas station can achieve economic benefits even if the usage rate is low.

In order to achieve the object of the present invention, the present invention proposes on the device side that one or more constant pressure reservoirs are connected to a fluid reservoir and a gas regulating unit via a fluid pump, and the gas regulating unit and one are moved. The storage container on the vehicle is connected to the device for filling the fuel. In other words, the gas station of the present invention includes a constant pressure storage unit and at least one fluid pump or gas delivery device, and there are no other facilities. According to an advantageous embodiment, more than one constant pressure reservoir of the gas station can be filled with fuel using a mobile storage container. In this way, the gas station only needs to have a constant pressure reservoir, and there is no need to have a gas storage container divided into a plurality of pressure levels. In addition, as long as a mobile compressor is used, the cost of setting the compressor can be saved. For example, a mobile storage container and/or a mobile compressor can be placed on a tank truck. This allows the constant pressure reservoir to be filled with fuel using a tanker equipped with a storage container and a compressor.

An advantageous embodiment is to design the individual device components of the gas station to be able to use hydrogen as a gas. This design is very important, especially for materials that choose to make constant pressure reservoirs and all seals and valves.

According to an advantageous embodiment, the individual device components of the gas station enable hydrogen to be charged and stored at a pressure of 235 to 5000 bar, 301 to 1200 bar, or preferably 620, 700, 850, 900, or 1000 bar. It is of course also possible to store hydrogen at a pressure below 235 bar, but this is not a good choice because of the small storage capacity.

According to an advantageous embodiment, the individual device components of the gas station enable hydrogen to be at a pressure of 235 to 1000 bar, 300 to 900 bar, or preferably 350 to 700 bar and -45 to 80 ° C, or preferably -40 ° C. The temperature to 60 ° C is delivered to the storage container of the mobile vehicle. In particular, the temperature can only differ by a maximum of +/- 10% from the desired temperature, and is preferably between -40 ° C and -33 ° C. To achieve this, an advantageous way is to cool the gas with a suitable heat exchanger before charging the gas, and to monitor the temperature throughout the filling process and adjust the temperature if necessary.

In order to achieve the object of the present invention, the method proposed by the present invention is to store the gas in more than one constant pressure accumulator and discharge it through a gas regulating unit and a fuel pump during the dumping phase, while at the same time In the stage, more than one of the pressures in the constant pressure reservoir remain unchanged to allow liquid to be delivered from the fluid reservoir to more than one of the constant pressure reservoirs. An advantageous embodiment is that the gas is hydrogen. Preferably, it is 235 to 5000 bar, 301 to 1200 bar, or preferably 620. 700, 850, 900, or 1000 bar of pressure storage gas, especially hydrogen. With a storage pressure of 700 bar, it takes only 2 to 10 minutes to load 2.0 to 10 kg of hydrogen into the empty tank of the car. Such a loading amount can usually be achieved for larger vehicles, such as buses, trucks, or street cleaning vehicles, without the need for a gas conditioning unit. In the case of a constant pressure reservoir, the loading is 10 to 40 kg of hydrogen and the required filling time is between 2 and 10 minutes.

For example, a car's hydrogen tank is filled with 3.5 kg of hydrogen. If the storage pressure of the constant pressure reservoir is 900 bar, the filling time is about 3 minutes. Depending on the ambient temperature, the hydrogen pressure in the car is between 650 and 900 bar.

When the amount of gas stored in the constant pressure storage unit is insufficient due to an increase in the number of vehicles requiring refueling, the gas station of the present invention may add a supply facility or install more constant pressure storage units. The advantage of this is that it can keep the investment and maintenance costs of the required gas stations at a low level when the hydrogen fuel vehicle is just introduced into the market, which contributes to the further popularization of gas stations. After a while, when hydrogen fuel vehicles are more popular in the market, resulting in an increase in the number of vehicles that need to be refueled, operators can reinvest in capital to expand the scale of gas stations. This helps gas station operators reduce the operational risks of their investment in new technologies. At the same time, increasing the distribution density of gas stations will also help people make the decision to switch to hydrogen fuel vehicles. The gas station of the present invention is also attractive to companies having fleets that use hydrogen as a fuel, such as companies with forklift trucks; and the gas station of the present invention is also advantageous for individuals who can accurately estimate the amount of hydrogen used. Because it can build a personalized independent hydrogen supply station. This is because the constant voltage storage unit can be manufactured in a modular manner. Don't realize the idea of building a personalized independent hydrogen supply station by choosing the number of constant pressure reservoirs.

In order to more clearly illustrate the nouns used in the present invention, the meanings of these terms are briefly described below.

A constant pressure storage unit refers to a device that can be used to charge a small, mobile, or stationary storage device. The constant pressure storage unit itself can be a stationary device, in particular as an integral part of the gas station. The constant pressure storage unit typically includes more than one constant pressure reservoir, a fluid supply device including at least one fluid pump and at least one fluid storage container, and optionally a gas conditioning unit to meet the gas requirements of the energy consumer. . Of course, in addition to this, it also includes various valves, regulators and sensors required to operate the facility.

When using a constant pressure reservoir, it is not necessary to provide a compressor or air compressor between the constant pressure reservoir and the energy consumer. This helps reduce investment and maintenance costs.

Conventional high-pressure storage devices undergo multiple load changes during evacuation and filling. The storage of gaseous fuels, especially hydrogen, is primarily the use of higher storage pressures to increase storage capacity. However, this will cause the load to rise further due to load changes. As the market's demand for hydrogen and hydrogen gas stations rises, so does the demand for stable, long-life, and less-required storage systems. However, the cost of traditional materials and facilities in this area is too high or not stable enough. As described in WO2015051894, a constant voltage storage unit may provide an alternative because it can substantially reduce the number of load changes. Therefore, the service life of the gas station can be greatly extended.

The so-called constant pressure reservoir refers to a device that supplies a predetermined constant pressure gas to a predetermined energy consuming device, and thus is also a high pressure gas reservoir. The pressure in the gas reservoir is usually dependent on the liquid level of the liquid gas therein, and at the same time as it is delivered to the energy consumer, the gas pressure must be adjusted by the compressor to be adapted to the energy consumer.

It is highly advantageous to deliver the gas at a constant pressure during the filling process, especially for small, mobile or stationary storage devices. A fixed compression ratio also contributes to the simplification of the filling process. In addition, a pressure can be selected that enables gas overflow.

The constant pressure reservoir can be filled in a storage phase using a mobile device, such as a suitable tank truck, or a stationary device, such as a boost device.

The constant pressure reservoir typically includes a cylinder that is divided into two zones by a movable dividing piston. The first zone functions to contain the gas and the second zone functions to contain the liquid. The gas referred to herein is preferably hydrogen or natural gas. The liquid referred to herein is preferably water or a non-flammable hydraulic oil, such as a hydraulic oil containing water and polyethylene glycol (for example, HFC), or a hydraulic oil containing mineral oil as a main component (for example, HLP). .

The principle of the constant pressure reservoir is that, in the storage phase, in the first zone, the pressure of the gas in the gas zone is kept constant because the volume of the first zone becomes larger, so the separation piston moves to make the volume of the second zone Become smaller. During the transfer phase, the volume of the first zone becomes smaller, allowing more liquid to be delivered to the second zone, while the volume of the second zone becomes larger, thereby maintaining the pressure in the first zone constant.

The gas stored in the constant pressure storage is ready for transport All steps for the energy consuming device are done in the gas conditioning unit. These steps may include drying steps, temperature matching and/or monitoring, pressure monitoring, and inspection and determination of delivery.

Embodiments of the present invention will be described below with reference to the drawings. In both embodiments, the same elements are denoted by the same element symbols.

10‧‧‧Supply unit

11‧‧‧ Hydrogen tank

12‧‧‧Mobile storage containers

20‧‧‧Compressor Station

21‧‧‧Air compressor unit

22‧‧‧Storage Control Unit

23‧‧‧High pressure storage

24‧‧‧ gas conditioning unit

25‧‧‧Constant pressure storage

26‧‧‧ Fluid pump and fluid reservoir

27‧‧‧Constant pressure storage unit

30‧‧‧ fuel pump

31‧‧‧ fuel pump valve

32‧‧‧Temperature compensation unit

33‧‧‧ Vehicles

Figure 1 shows the structure of a prior art gas station in a schematic manner.

Fig. 2 is a view showing the structure of the gas station of the present invention in a schematic manner.

These embodiments include the most important components of a gas station. In order to simplify the drawing, components that are small in size and are familiar to those skilled in the art are not drawn in the drawings, such as valves, regulators, simple pumps, sensors, and the like.

Figure 1 shows a hydrogen gas station of the prior art. This gas station is provided with a supply unit 10, which in this embodiment is constituted by a stationary hydrogen tank 11. Hydrogen is usually stored in a hydrogen tank at a pressure of 1 to 220 bar. The hydrogen tank 11 is connected to the compressor 20, in particular to the compressor 21 of the compressor. The air compressor 21 is connected to a high pressure (e.g., 1000 bar) reservoir 23 via a storage control unit 22 or to a gas conditioning unit 24. The gas adjusting unit 24 adjusts the temperature of the hydrogen to -20 ° C to -50 ° C and is connected to the fuel pump 30. The fuel pump 30 is mainly composed of a fuel pump valve 31 and a temperature compensating unit 32, wherein the temperature compensating unit 32 is tasked to maintain the temperature at -50 ° C to +80 ° C, especially -40 ° C to -20 ° C. The fuel pump 30 is connected to a mobile storage tank. Especially connected to cars, buses, locomotives, or other hydrogen-fueled vehicles.

Figure 2 shows a gas station of the present invention. Such a gas station does not need to be equipped with a stationary hydrogen tank, but supplies hydrogen through a mobile storage container 12, preferably a storage tank for a tank truck. Hydrogen is directly stored in the constant pressure reservoir 25. The supplied hydrogen has been supplied at a pressure of 500 to 900 bar, or the pressure is increased to a corresponding storage pressure by a mobile compressor, preferably located on the tanker. The constant pressure reservoir is only connected to the fluid pump and fluid reservoir 26 which maintains the pressure at a constant pressure. Further, the constant pressure accumulator 25 is also connected to the gas regulating unit 24. The gas regulating unit 24 functions exactly the same as the fuel pump 30 in Fig. 1.

During the storage phase of the constant pressure storage unit 27, more than one constant pressure reservoir 25 is filled or refilled. Hydrogen is typically supplied by the mobile unit 12. It is usually necessary to load hydrogen into a constant pressure reservoir via an air compressor and/or a cryopump, a so-called refrigerating pump. During this process, hydrogen will drive the separation piston, that is, mechanical work will be generated to cause the separation piston to move axially within the constant pressure reservoir 25. Therefore, the volume of the liquid region becomes small, and the volume of the gas region becomes large.

During storage, the gas pressure in the constant pressure reservoir 25 must also remain constant, that is, the set maximum storage pressure is reached. This pressure is adjusted or ensured through the regulating valve.

The transfer phase of the constant pressure storage unit 27 is to charge hydrogen to the energy consumer 33 via the delivery device 30, particularly via the gas conditioning unit 24. In order to maintain a constant pressure, the volume of the gas zone becomes small. In order to reduce the volume of the gas zone, the liquid in the fluid reservoir is lost by the fluid pump 26. The second zone is sent to the constant pressure accumulator while the movable dividing piston produces an axial movement, thereby making the volume of the second zone larger and the volume of the gas zone becoming smaller.

12‧‧‧Mobile storage containers

24‧‧‧ gas conditioning unit

25‧‧‧Constant pressure storage

26‧‧‧ Fluid pump and fluid reservoir

27‧‧‧Constant pressure storage unit

30‧‧‧ fuel pump

31‧‧‧ fuel pump valve

32‧‧‧Temperature compensation unit

33‧‧‧ Vehicles

Claims (9)

A gas station whose task is to load a gas into a storage container provided on a mobile vehicle (33), characterized in that more than one constant pressure reservoir (25) is connected to a fluid reservoir (26) via a fluid pump (26) And a gas regulating unit (24) is connected, and the gas regulating unit (24) is connected to a device (30) for filling the storage container on the mobile vehicle (33). A gas station according to claim 1, wherein more than one of said constant pressure accumulators (25) is filled with fuel by means of a mobile storage container (12). A gas station as claimed in claim 1 or 2, wherein the components of each of the gas stations are capable of using hydrogen as a gas. A gas station according to any one of claims 1 to 3, wherein the components of the respective stations of the gas station enable hydrogen to be 235 to 5000 bar, 301 to 1200 bar, or preferably 620, 700, 850, 900, or The pressure of 1000 bar is filled and stored. A gas station according to any one of claims 1 to 4, wherein the components of the respective stations of the gas station enable the hydrogen to be at a pressure of 235 to 1000 bar, 301 to 900 bar, or preferably 350 to 700 bar and -45 ° C. A temperature of up to 80 °C is delivered to the storage container of the mobile vehicle. A method of loading a gas into a storage container on a mobile vehicle (33) at a gas station, characterized in that the gas is stored in more than one constant pressure reservoir (25) and is regulated via a gas during the dumping phase The unit (24) and a fuel pump (30) are discharged while at the transfer storage stage, more than one pressure in the constant pressure reservoir (25) remains unchanged to allow liquid to be transported from the fluid reservoir (26) More than one of the constant pressure storage Inside the device (25). 7. The method of claim 6, wherein the gas is hydrogen. The method of claim 6 or 7, wherein the hydrogen is charged and stored at a pressure of 235 to 5000 bar, 301 to 1200 bar, or preferably 620, 700, 850, 900, or 1000 bar. The method of any one of claims 6 to 8, wherein the gas can be delivered to the mobile at a pressure of 235 to 1000 bar, 301 to 900 bar, or preferably 350 to 700 bar and a temperature of -45 ° C to 80 ° C. The storage container of the vehicle.