CN216044081U

CN216044081U - CNGV fuel supply system for storing low-temperature LNG and high-pressure CNG

Info

Publication number: CN216044081U
Application number: CN202121918891.0U
Authority: CN
Inventors: 洪讵; 翟书胜
Original assignee: Beijing Beidou Times Technology Development Co ltd
Current assignee: Beijing Beidou Times Technology Development Co ltd
Priority date: 2021-08-16
Filing date: 2021-08-16
Publication date: 2022-03-15
Anticipated expiration: 2031-08-16

Abstract

The application discloses CNGV fuel supply system of storage low temperature LNG and high-pressure CNG includes: a low-temperature high-pressure gas cylinder, a gas return pipe, a normal-temperature high-pressure gas cylinder and a gas end. The low-temperature high-pressure gas cylinder is provided with two openings, one end of the air return pipe extends into the upper side of an inner cavity of the low-temperature high-pressure gas cylinder through the first opening, the normal-temperature high-pressure gas cylinder is connected with the other end of the air return pipe to receive compressed natural gas generated after the low-temperature high-pressure gas cylinder is vaporized, one end of the liquid filling pipe extends into the lower side of the inner cavity of the low-temperature high-pressure gas cylinder through the second opening, and the other end of the liquid filling pipe is connected with the gas end through the heater and the pressure reducer. The gas end is respectively communicated with the normal-temperature high-pressure gas cylinder and the low-temperature high-pressure gas cylinder selectively to obtain the normal-temperature low-pressure natural gas. The gas natural gas is divided, so that the pressure in the low-temperature high-pressure gas cylinder can be reduced and is always below 35MPa, and the storage time of low-temperature fuel can be reduced, so that the low-temperature high-pressure gas cylinder is not required to be manufactured by adopting high-pressure-resistance materials and high-heat-insulation materials, and the manufacturing cost is reduced.

Description

CNGV fuel supply system for storing low-temperature LNG and high-pressure CNG

Technical Field

The application relates to the field of new energy, in particular to a CNGV fuel supply system for storing low-temperature LNG and high-pressure CNG.

Background

LNG (Liquefied Natural Gas) is a cryogenic liquid fuel produced from raw Natural Gas by a continuous refrigeration process and can be transported across the ocean, over the ocean, and to various local filling stations and end users directly from door to door by cold chain transportation. The CNG (Compressed Natural Gas) is an ideal petrochemical clean fuel in internal combustion automobiles because the CNG has the advantages of perfect preparation technology, convenient cold chain transportation, pure quality, safe use, high combustion heat value, high energy density, more stored fuels, short liquid adding time, high filling efficiency and the like and is superior to CNG (Compressed Natural Gas); meanwhile, compared with fuel oil, the operation cost of LNG can be saved by 20-30%; therefore, LNG can replace gasoline and diesel oil with serious pollution in large quantity, even pipeline natural gas CNG, and is widely used in various LNGVs (liquefied natural gas vehicles).

In the low temperature, low pressure vessel (dewar) of the LNGV, a mixture of liquid phase LNG and gaseous phase CNG is filled and stored. When the temperature is too high and the saturation pressure is too high (more than 1.6Mpa), the Boil-Off Gas (BOG) of natural Gas is emitted and the environment is polluted. LNG remains liquid for a longer period of time only in environments below the critical temperature. Therefore, the dewar should have a super strong heat insulation function to ensure the stored LNG to be kept in a liquid state for 5 days, so as to meet the requirement of normal operation of the vehicle.

Due to the influence of the bleed BOG, the liquid fuel LNG is only used for large-scale, long-distance and open-air parked vehicles at present, but not for medium and small natural gas vehicles. Small dewars are dangerous due to the relatively excessive BOG discharge. Thus, regulations mandate that LNG be prohibited from being stored and applied at the following locations: vehicles with engine displacement less than 2 liters, dewars with volume less than 150 liters, and natural gas vehicles parked in closed garages.

Most (over 90%) natural gas automobiles currently use only compressed natural gas CNG as a fuel. High-pressure CNG of 20Mpa is filled and stored from a pipeline gas CNG filling station (or LNG-CNG vaporization station) and is used for burning an engine after decompression. Although the storage mode does not generate gas leakage, the storage mode has low density and short driving range due to gas storage. The application, development and popularization of the small-sized natural gas passenger vehicle are limited (only 200 kilometers). The above-mentioned drawbacks can only be overcome if the storage pressure of the gas cylinder for CNGV vehicles is increased. The storage pressure of the gas cylinder is increased from 20MPa to 30-35MPa, so that the effect is obvious, and the driving range can be increased to more than 300 kilometers.

However, increasing the CNG pressure increases the cost of the cylinders and the capital and energy consumption of the gas station. Especially, when the pressure is increased to more than 35Mpa, the gas storage cost and the inflation time of the vehicle are greatly increased. The storage pressure of the gas cylinder for CNGV vehicles is not more than 35 MPa.

The technology of directly filling and storing the Liquid Natural Gas (LNG) on the small-sized natural gas passenger vehicle and heating and vaporizing the LNG into the low-pressure gas (CNG) is the best scheme for thoroughly solving the mileage anxiety of the small-sized natural gas passenger vehicle. And is an effective way for small passenger vehicles to be able to use LNG. Thus, the driving range of CNGV can be increased; the use convenience can be improved, and the dependence of a natural gas vehicle on pipeline natural gas and a high-pressure gas station can be eliminated; the method is an effective measure for treating urban atmospheric pollution (in a relatively long period) during the transition period from the fuel vehicle to the electric vehicle. Will cause catastrophic changes to the natural gas automotive industry and its fuel supply systems. At that time, the pipeline gas filling station can be decommissioned, and only enough LNG filling stations are needed to be provided, so that unified fuels can be provided for various NGV vehicles.

SUMMERY OF THE UTILITY MODEL

The present application is directed to solving at least one of the problems in the prior art. To this end, an object of the present application is to provide a CNGV (natural gas vehicle) fuel supply system for enabling storage of low-temperature LNG and high-pressure CNG, respectively, which can directly charge and store low-temperature LNG, and also can store vaporized normal-temperature CNG by splitting, without releasing a dispersed gas of natural gas.

The CNGV fuel supply system storing low-temperature LNG and high-pressure CNG according to an embodiment of the present invention includes: a cryogenic high pressure gas cylinder having a first opening; one end of the air return pipe extends into the upper side of the inner cavity of the low-temperature high-pressure gas cylinder through the first opening; the normal-temperature high-pressure gas cylinder is connected with the other end of the gas return pipe to receive compressed natural gas generated after the low-temperature high-pressure gas cylinder is vaporized; and the gas using end is selectively communicated with the normal-temperature high-pressure gas cylinder and the low-temperature high-pressure gas cylinder respectively.

According to the CNGV fuel supply system for storing low-temperature LNG and high-pressure CNG provided by the embodiment of the utility model, the normal-temperature high-pressure gas cylinder is additionally arranged, the gaseous natural gas after gas vaporization is divided, the pressure in the low-temperature high-pressure gas cylinder can be reduced, the working safety of the low-temperature high-pressure gas cylinder can be improved, the pressure is always below 35MPa, the storage time of low-temperature fuel can be reduced, the low-temperature high-pressure gas cylinder is not required to be manufactured by adopting high-pressure-resistant materials and high-heat-insulation materials, and the manufacturing cost can be reduced. And the filled liquid natural gas can be kept in a storage state in a short period, so that the storage capacity is increased, and the endurance mileage of the vehicle can be improved. And the BOG of the bleed gas can not be released when in use, the safety is improved, the BOG can be applied to passenger vehicles of medium and small vehicles, and the applicability of directly and quickly filling the liquid natural gas fuel is strong.

In some embodiments, the CNGV fuel supply system storing cryogenic LNG and high-pressure CNG further comprises: one end of the liquid filling pipe extends into the lower side of the inner cavity of the low-temperature high-pressure gas cylinder through the first opening, and the other end of the liquid filling pipe is selectively communicated with the gas using end.

In some embodiments, the cryogenic high pressure gas cylinder further has a second opening, and the CNGV fuel supply system storing cryogenic LNG and high pressure CNG further comprises: one end of the liquid filling pipe can extend into the lower side of the inner cavity of the low-temperature high-pressure gas cylinder through the second opening, and the other end of the liquid filling pipe is selectively communicated with the gas using end.

Furthermore, a first valve body is arranged between the other end of the air return pipe and the air using end, a second valve body is arranged between the other end of the liquid charging pipe and the air using end, and a third valve body is arranged between the normal-temperature high-pressure air bottle and the air using end.

Specifically, the first valve body, the second valve body and the third valve body are all hydraulic electrically-controlled one-way valves.

In some embodiments, the CNGV fuel supply system for a vehicle storing cryogenic LNG and high-pressure CNG further comprises: the gas-liquid separation device comprises a liquid injection pipe and an exhaust pipe, wherein one end of the liquid injection pipe is connected with the other end of the liquid filling pipe, the liquid injection pipe is used for filling liquid natural gas into the low-temperature high-pressure gas cylinder, and a fourth valve body is arranged on the liquid injection pipe; one end of the air exhaust pipe is connected with the other end of the air return pipe, the air exhaust pipe is used for exhausting residual air in the low-temperature high-pressure air bottle, and a fifth valve body is arranged on the air exhaust pipe; the liquid injection pipe and the air exhaust pipe can exhaust residual gas in the low-temperature high-pressure gas cylinder when used for filling fuel, so that the low-temperature high-pressure gas cylinder can smoothly fill the fuel, and the fourth valve body and the fifth valve body are both mechanical controllable one-way valves.

Optionally, an overflow valve is disposed between the normal-temperature high-pressure gas cylinder and the other end of the gas return pipe, so that only vaporized natural gas can be introduced into the normal-temperature high-pressure gas cylinder.

In some embodiments, the gas using end comprises: the low-temperature high-pressure gas cylinder is communicated with a heat exchange tube in the first heat exchanger in a selectable mode, and the heat exchange tube in the first heat exchanger is communicated with the first pressure reducer; the heat exchange tube in the second heat exchanger is communicated with the second pressure reducer.

In some embodiments, the normal-temperature high-pressure gas cylinder is additionally arranged to shunt the gaseous natural gas, so that the pressure in the low-temperature high-pressure gas cylinder can be reduced and is always below 35Mpa, and the requirement on the high-pressure safety of the gas cylinder is reduced.

In some embodiments, the normal-temperature high-pressure gas cylinder is additionally arranged, so that the storage time of low-temperature fuel can be shortened, and the requirement on the low-temperature heat insulation property of the gas cylinder is lowered.

In some embodiments, it is not necessary to use materials with high pressure resistance and high heat insulation to manufacture the low-temperature high-pressure gas cylinder, so that the manufacturing cost can be reduced.

Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

Drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic structural view of a fuel supply system according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of a fuel supply system according to another embodiment of the present invention;

FIG. 3 is a graph of the change between storage pressure and density of gaseous natural gas according to an embodiment of the utility model;

FIG. 4 is a schematic diagram of a cryogenic high pressure gas cylinder according to an embodiment of the utility model;

FIG. 5 is a schematic structural view of a fuel supply system according to yet another embodiment of the present invention;

fig. 6 is a schematic configuration diagram of a fuel supply system according to still another embodiment of the present invention.

Reference numerals:

a fuel supply system 100,

A low-temperature high-pressure gas cylinder 1, a first opening 11, a second opening 12, an inner cylinder 13, a heat insulation layer 14, an outer shell 15,

A muffler 2, a first valve body 21, an overflow valve 22,

A normal temperature high pressure gas cylinder 3, a third valve body 31,

A gas using end 4, a first heat exchanger 41, a first pressure reducer 42, a second heat exchanger 43, a second pressure reducer 44, a third heat exchanger 45, a third pressure reducer 46,

A liquid charging pipe 5, a second valve body 51,

The liquid injection pipe 6, the fourth valve body 61,

Air exhaust pipe 7 and fifth valve body 71

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present application. In the description of the present application, "the first feature" and "the second feature" may include one or more of the features. In the description of the present application, "a plurality" means two or more.

A CNGV fuel supply system for storing low-temperature LNG and high-pressure CNG according to an embodiment of the present application will be described with reference to fig. 1 to 6, where NG is english abbreviation of normal natural gas, LNG is english abbreviation of liquid natural gas, CNG is english abbreviation of gaseous natural gas, BOG is english abbreviation of dispersed gas, and CNGV is english abbreviation of natural gas vehicle.

The CNGV fuel supply system 100 storing cryogenic LNG and high-pressure CNG includes: the low-temperature high-pressure gas cylinder 1, the muffler 2, normal atmospheric temperature high-pressure gas cylinder 3 and gas end 4, low-temperature high-pressure gas cylinder 1 has first opening 11, and the one end of muffler 2 stretches into the inner chamber upside of low-temperature high-pressure gas cylinder 1 through first opening 11, and normal atmospheric temperature high-pressure gas cylinder 3 links to each other with the other end of muffler 2 in order to receive the compressed natural gas that low-temperature high-pressure gas cylinder 1 produced after the vaporization, and gas end 4 communicates with normal atmospheric temperature high-pressure gas cylinder 3 and low-temperature high-pressure gas cylinder 1 selectively respectively.

In some embodiments, the cryogenic high-pressure gas cylinder 1 may be a 65-liter seamless container capable of withstanding the use temperature of-162 ℃ and the bearing pressure of 60MPa, and the cryogenic high-pressure gas cylinder 1 is used for containing cryogenic liquid natural gas and gaseous natural gas, it is understood that the liquid natural gas is vaporized by heat, so that the cryogenic high-pressure gas cylinder 1 is not loaded with pure liquid natural gas but with a mixture of liquid natural gas and gaseous natural gas.

At present, the gas consumption of a small passenger vehicle CNGV in hundred kilometers is about 7 standard square. Converted into weight: 7 × 0.7174 is 5.0218 kg/hundred kilometers, so that the 500 kilometer gas consumption is 5 × 7 × 35 standard square natural gas, which is converted into 5 × 3500/625 × 56 liters of LNG volume, or into 25.1 kg of liquefied natural gas by weight. When the volume of the gas cylinder is selected, the requirement of the existing regulation is complied with, and the maximum filling amount of the liquefied natural gas is not more than 90 percent of the volume of the gas cylinder. The minimum volume of the cylinder was calculated to be 56/0.9-62.22 litres. And finally, 65 liters of low-temperature high-pressure gas cylinders 1 with the bearing pressure of 60MPa are selected, 56 liters of LNG are stored, and the small passenger car can be ensured to run for 500 kilometers.

When 25.1 kg of liquefied natural gas filled in the low-temperature high-pressure gas cylinder 1 is completely vaporized, namely 25.1 kg of liquefied natural gas is completely converted into gaseous natural gas in the 65L low-temperature high-pressure gas cylinder 1, the formed highest pressure value is only 53.85MPa, and the low-temperature high-pressure gas cylinder 1 can meet the requirements. In the actual use process, the liquefied natural gas is consumed continuously, the amount of the gaseous natural gas generated by actual vaporization is reduced, and the formed pressure is smaller than the highest bearing pressure of the low-temperature high-pressure gas cylinder 1.

It is worth mentioning that in the existing relevant standards for LNGV dewars for cryogenic lng, the lng is required to remain liquid for five days, with the aim of delaying the vaporization of the lng, reducing the release of bleed air, and reducing the pressure in the dewar, maintaining low gas consumption and safe operation of the vehicle. And the low temperature high pressure gas cylinder 1 in this application embodiment can maintain the low gas consumption and safe operation of the vehicle even if the carried liquefied natural gas is completely vaporized because of the high pressure that can be carried, so the low temperature high pressure gas cylinder 1 in this application embodiment need not maintain the liquid state of filling into LNG for a long time, and the heat-insulating property of the gas cylinder can be greatly simplified, and the manufacturing cost and the manufacturing difficulty can be reduced.

According to the CNGV fuel supply system 100 for storing low-temperature LNG and high-pressure CNG provided by the embodiment of the application, the normal-temperature high-pressure gas cylinder 3 is additionally arranged, so that vaporized gaseous natural gas in the low-temperature high-pressure gas cylinder 1 is specially stored, gas fuel can be stored in a shunting manner, and the pressure in the low-temperature high-pressure gas cylinder 1 is reduced.

According to the graph shown in fig. 3, the relation between the storage pressure and the density of the gaseous natural gas can be obtained, the volume of the normal-temperature high-pressure gas cylinder 3 can be calculated according to the graph, when the pressure is less than 20MPa, the pressure and the storage density of the gas cylinder are basically linearly related, and the speed of filling the gaseous natural gas into the normal-temperature high-pressure gas cylinder 3 is high; when the pressure is increased from 20MPa to 35MPa, the linear correlation between the pressure and the storage density is not formed, because the molecular weight of the natural gas is larger, the molecular number in the container is increased continuously in the compression process, the collision is aggravated, the volume cannot be reduced proportionally, the gas heating phenomenon is accompanied, the pressure is higher, the heating is more serious, the speed of filling the gaseous natural gas into the normal-temperature high-pressure gas cylinder 3 is reduced, after the pressure exceeds 35MPa, the heating is more serious, the storage density is increased more slowly, the storage efficiency is obviously reduced, and the speed of filling the gaseous natural gas into the normal-temperature high-pressure gas cylinder 3 is greatly reduced. Therefore, in view of the cost of manufacturing the normal-temperature high-pressure gas cylinder 3 and the efficiency of storing the normal-temperature high-pressure gas cylinder 3, the storage pressure of the normal-temperature high-pressure gas cylinder 3 should not be too high, and the maximum limit value should be 35 MPa.

For ease of application, the curve shown in FIG. 3 may be converted to the relationship of storage pressure and density for gaseous natural gas as shown in Table 1.

Working pressure MPa	5	20	25	30	35
						Density kg/m ³	40	178.5	215	237.31	257.57

TABLE 1

According to the data in table 1, under different working pressures, which can be calculated according to the formula (1-1),

V＝m/ρ (1-1)

where V is the volume of the gaseous natural gas and m is the total weight of the gaseous natural gas, it can be seen from the above that the weight of the liquid natural gas with a gas consumption of 500 km is 25.1 kg, while the weight of the vaporized gaseous natural gas is 25.1 kg, i.e. 25100 kg, and ρ is the density of the gaseous natural gas.

When the pressure requirement in the volume of the fuel supply system 100 reaches 35MPa, the total volume of the gaseous natural gas is as follows: v₃₅97.45 liters for (25100/257.57). The volume of the low-temperature high-pressure gas cylinder 1 is 65 liters, and although the low-temperature high-pressure gas cylinder 1 can bear 25.1 kilograms of liquefied natural gas and completely vaporize, the pressure generated after the vaporization of the low-temperature high-pressure gas cylinder 1 with the volume of 65 liters is 53.85MPa, so that the normal-temperature high-pressure gas cylinder with the volume of 97.45-65 liters to 32.45 liters needs to be additionally arrangedThe gas cylinder 3 is rounded to 35 liters, namely the internal pressure of the volume of the completely vaporized liquid natural gas is reduced to 35 MPa.

Similarly, when the pressure requirement in the volume of the fuel supply system 100 reaches 30MPa, a normal-temperature high-pressure gas cylinder 3 with the volume of 41 liters needs to be added; when the pressure requirement on the volume of the fuel supply system 100 reaches 25MPa, a normal-temperature high-pressure gas cylinder 3 with the volume of 55 liters needs to be added; when the pressure requirement on the volume of the fuel supply system 100 reaches 20MPa, a normal-temperature high-pressure gas cylinder 3 with the volume of 75 liters needs to be added.

Therefore, when the normal-temperature high-pressure gas cylinder 3 is added, 56 liters of liquid natural gas can be contained in the low-temperature high-pressure gas cylinder 1, and the pressure generated after all the liquid natural gas is vaporized does not need to be borne independently, that is, the pressure of the highest 53.85MPa does not need to be borne by the low-temperature high-pressure gas cylinder 1, the gaseous natural gas is divided by additionally arranging the high-pressure normal-temperature gas cylinders with different volumes, the pressure in the low-temperature high-pressure gas cylinder 1 can be reduced, and the working safety of the low-temperature high-pressure gas cylinder 1 can be improved.

In one embodiment of the present application, the low-temperature high-pressure gas cylinder 1 is a 65-liter seamless container capable of withstanding the use temperature of-162 ℃ and the bearing pressure of 35MPa, and the normal-temperature high-pressure gas cylinder 3 is a 35-liter seamless container with the bearing pressure of 35 MPa.

Compared with the arrangement of only one low-temperature high-pressure gas cylinder 1, the normal-temperature high-pressure gas cylinder 3 can reduce the bearing pressure of the low-temperature high-pressure gas cylinder 1, a Dewar bottle with high heat insulation performance is not needed, a material with high pressure resistance performance is not needed, and the manufacturing cost of the low-temperature high-pressure gas cylinder 1 can be reduced. Compared with the CNGV fuel supply system 100 which only uses gaseous natural gas and stores low-temperature LNG and high-pressure CNG, the CNGV fuel supply system can use the liquid natural gas as a storage state, increases the storage capacity, can improve the endurance mileage of the vehicle, improves the safety, can not release the diffused gas during use, improves the safety, can be applied to medium and small vehicles, and has strong applicability.

In some other embodiments of the present application, as shown in fig. 4, the insulation layer 14, the wrapping material, and the inner cylinder 13 structure of the cryogenic high-pressure gas cylinder 1 are simplified structures. The low-temperature high-pressure gas cylinder 1 in the embodiment of the application is not high in pressure, and the long-time heat preservation of the liquefied natural gas is not needed, so that the structure and the winding process of the low-temperature high-pressure gas cylinder 1 can be simplified, and the manufacturing cost of the low-temperature high-pressure gas cylinder 1 is further reduced. Specifically, the inner cylinder 13 of the low-temperature high-pressure gas cylinder 1 can be made of low-temperature-resistant aluminum alloy or stainless steel, the heat insulation layer 14 is used for isolating the heat of the inner cylinder 13, specific setting can be carried out according to different use conditions, if the gas cylinder is required to be kept cold for a long time, a heat insulation material with strong heat insulation performance is filled in a heat insulation space, and high vacuum is pumped; if long-time cold insulation is not required, the filling of heat insulation materials is not required, and only semi-vacuum is kept; if the fuel in the bottle is not required to be kept in a low-temperature liquid state, the vacuum can not be pumped, and even circulating water is used for heating. Further, low temperature high pressure gas cylinder 1 of this application still includes shell 15, shell 15 can be made by ordinary stainless steel or nonmetal, be formed with installation space in the shell 15, interior bottle 13 is fixed in installation space, and be formed with the interval space between interior bottle 13 and the shell 15, it can be understood here, because interior bottle 13 is interior to be stored with low temperature liquefied natural gas, make the temperature of the outer wall of interior bottle 13 also be in the low temperature state easily, the outer wall of the interior bottle 13 of low temperature state, increase installation difficulty and installation cost on the car easily, and simultaneously, avoid low temperature outer wall to become the potential safety hazard, the frostbite contacter. From this, through the shell 15 that sets up, install interior bottle 13 in shell 15 to make and be formed with the interval space between interior bottle 13 and the shell 15, can keep apart interior bottle 13 and external environment to a certain extent, thereby can install under the prerequisite of bottle 13 in not damaging, also reduce low temperature high pressure gas cylinder 1's installation requirement easily, thereby reduce installation cost, still be difficult for bringing frostbite operating personnel's potential safety hazard.

The low-temperature high-pressure gas cylinder 1 stores liquid natural gas, the gas return pipe 2 guides the gaseous natural gas vaporized in the low-temperature high-pressure gas cylinder 1 to the normal-temperature high-pressure gas cylinder 3, and the normal-temperature high-pressure gas cylinder 3 stores the gaseous natural gas vaporized in the low-temperature high-pressure gas cylinder 1. The gas end 4 is respectively communicated with the normal-temperature high-pressure gas cylinder 3 and the low-temperature high-pressure gas cylinder 1, can be selectively communicated with the normal-temperature high-pressure gas cylinder 3 and/or the low-temperature high-pressure gas cylinder 1, and can be used for heating the gaseous natural gas in the normal-temperature high-pressure gas cylinder 3 and then burning an engine, and the gas end 4 can also be used for heating the liquid natural gas or the gaseous natural gas in the low-temperature high-pressure gas cylinder 1 and then burning the engine.

According to the CNGV fuel supply system 100 for storing low-temperature LNG and high-pressure CNG of the embodiment of the application, the normal-temperature high-pressure gas cylinder 3 is additionally arranged to split the gaseous natural gas, so that the pressure in the low-temperature high-pressure gas cylinder 1 can be reduced, and the low-temperature high-pressure gas cylinder 1 does not need to be made of high-pressure-resistance materials and high-heat-insulation materials, so that the manufacturing cost can be reduced. And the liquefied natural gas can be used as a storage state, so that the storage capacity is increased, and the endurance mileage of the vehicle can be improved. When in use, the air can not be released, the safety is improved, and the air release device can be applied to medium and small vehicles and has strong applicability.

In some embodiments, as shown in fig. 1, the CNGV fuel supply system 100 for a vehicle storing low-temperature LNG and high-pressure CNG further includes: and one end of the liquid charging pipe 5 extends into the lower side of the inner cavity of the low-temperature high-pressure gas cylinder 1 through the first opening 11, and the other end of the liquid charging pipe 5 is selectively communicated with the gas using end 4.

The liquid filling pipe 5 is used for filling the liquefied natural gas into the low-temperature high-pressure gas cylinder 1 and can be selectively connected with the gas using end 4, so that the liquefied natural gas in the low-temperature high-pressure gas cylinder 1 is heated and then is used by an engine.

It can be understood that the liquid filling pipe 5 is connected with the liquid filling pipe 6 to fill the low-temperature high-pressure gas cylinder 1 with the liquefied natural gas, but at the initial filling stage of the liquefied natural gas, because the low-temperature high-pressure gas cylinder 1 is still at room temperature, the liquefied natural gas boils, gaseous natural gas is generated, and the incompletely used gaseous natural gas may remain in the low-temperature high-pressure gas cylinder 1, so that the saturated gas pressure in the low-temperature high-pressure gas cylinder 1 gradually rises, and when the gas pressure in the low-temperature high-pressure gas cylinder 1 exceeds the filling pressure of the liquid filling station, the liquefied natural gas cannot be filled.

Therefore, an exhaust system is required to be arranged to exhaust the residual gas in the low-temperature high-pressure gas cylinder 1, reduce the pressure in the cylinder and ensure that the liquefied natural gas can be smoothly charged. Alternatively, the gas return pipe 2 may function to discharge the residual gas to the outside of the low-temperature high-pressure gas cylinder 1, and the residual gas is discharged from the other end of the gas return pipe 2 to the outside, thereby reducing the pressure in the low-temperature high-pressure gas cylinder 1. In some embodiments, two ejector rod devices are arranged in a liquid filling gun in the liquid filling station, two mechanical one-way valves can be controlled to be simultaneously connected with the liquid filling pipe 5 and the gas return pipe 2, and when the low-temperature high-pressure gas cylinder 1 is filled with the liquefied natural gas, residual gas of the liquefied natural gas is extracted through the gas return pipe 2, so that the filling speed of the liquefied natural gas is accelerated.

Therefore, the liquid charging pipe 5 and the gas return pipe 2 are arranged at the first opening 11 of the low-temperature high-pressure gas cylinder 1, so that residual gas of the gaseous natural gas can be discharged while filling the liquefied natural gas, while the vaporized natural gas in the low-temperature high-pressure gas cylinder 1 is positioned above the liquefied natural gas, the liquid charging pipe 5 is arranged below the gas return pipe 2, so that the liquefied natural gas can be filled and the gaseous natural gas can be discharged, mutual interference can be reduced, and the situation that the liquid natural gas is pumped out by the gas return pipe 2 is avoided.

In other embodiments, as shown in fig. 2 and 4, the cryogenic high-pressure gas cylinder 1 further has a second opening 12, and the CNGV fuel supply system 100 for storing cryogenic LNG and high-pressure CNG further includes: and a liquid charging pipe 5, wherein one end of the liquid charging pipe 5 extends into the low-temperature high-pressure gas cylinder 1 through a second opening 12, and the other end of the liquid charging pipe 5 is selectively communicated with the gas using end 4.

The liquid charging pipe 5 and the gas return pipe 2 are arranged in a separated mode and are respectively positioned at two openings at two sides of the low-temperature high-pressure gas cylinder 1, so that the working interference of the liquid charging pipe 5 and the gas return pipe 2 can be further reduced, and the working stability of the liquid charging pipe 5 and the gas return pipe 2 is improved.

In some embodiments, a gas return pipe 2 and a liquid charging pipe 5 are arranged at the first opening 11 of the low-temperature high-pressure gas cylinder 1, a gas return pipe 2 and a liquid charging pipe 5 are also arranged at the second opening 12 of the low-temperature high-pressure gas cylinder 1, and one end of the liquid charging pipe 5 extending into the low-temperature high-pressure gas cylinder 1 is positioned at the lower side of one end of the gas return pipe 2 extending into the low-temperature high-pressure gas cylinder 1. Both sides at low temperature high pressure gas cylinder 1 all are provided with muffler 2 and liquid charging pipe 5, and low temperature high pressure gas cylinder 1's structural symmetry is convenient for arrange, need not to look for the one end of installing liquid charging pipe 5 alone when filling liquid natural gas, convenient to use. And the liquid charging pipe 5 and the air return pipe 2 at the two ends can be selectively connected with the gas using end 4, so that the conveying capacity of the gas using end 4 can be improved, and the functionality of the fuel supply system 100 is improved.

The low temperature high pressure gas cylinder 1 of this application embodiment can have horizontal and vertical according to placing the demand, and horizontal herein indicates to place along the left and right sides direction as shown in fig. 1, and vertical indicates to place as the vertical direction that fig. 2 shows, compares in horizontal low temperature high pressure gas cylinder 1, and vertical low temperature high pressure gas cylinder 1 is less in the ascending volume of horizontal direction, and occupation space is little, is convenient for arrange on small vehicle.

In order to meet the requirements of natural gas filling and natural gas use after horizontal and vertical placement of the low-temperature high-pressure gas cylinder 1, some arrangements are needed for the liquid feeding pipe and the gas return pipe 2, in the embodiment of the vertical low-temperature high-pressure gas cylinder 1, the first opening 11 of the low-temperature high-pressure gas cylinder 1 is arranged above the vertical direction, the second opening 12 of the low-temperature high-pressure gas cylinder 1 is arranged below the vertical direction, an air return pipe 2 is arranged at the first opening 11, one end of the air return pipe 2 extends into the low-temperature high-pressure gas cylinder 1 through the first opening 11, a normal-temperature high-pressure gas cylinder 3 is connected with the other end of the air return pipe 2 to receive compressed natural gas generated when the low-temperature high-pressure gas cylinder 1 is heated, a liquid charging pipe 5 is arranged at the second opening 12, one end of the liquid charging pipe 5 extends into the low-temperature high-pressure gas cylinder 1 through the second opening 12, and the other end of the liquid charging pipe 5 is selectively communicated with the gas using end 4.

Further, as shown in fig. 1, a first valve 21 is disposed between the other end of the gas return pipe 2 and the gas using end 4, a second valve 51 is disposed between the other end of the liquid charging pipe 5 and the gas using end 4, and the first valve 21 and the second valve 51 can control the communication between the low-temperature high-pressure gas cylinder 1 and the gas return end.

When the first valve body 21 controls the air return pipe 2 to be communicated with the gas using end 4, the gaseous natural gas in the low-temperature high-pressure gas cylinder 1 can be guided to the gas using end 4, and the gas using end 4 is processed and then used by an engine; when the second valve body 51 controls the liquid charging pipe 5 to be communicated with the gas using end 4, the liquefied natural gas in the low-temperature high-pressure gas cylinder 1 can be guided to the gas using end 4, and the gas using end 4 is heated and then used by an engine. When the first valve body 21 controls the gas return pipe 2 to be disconnected from the gas using end 4 and the second valve body 51 controls the liquid charging pipe 5 to be disconnected from the gas using end 4, the gaseous natural gas and the liquid natural gas are both limited in the low-temperature high-pressure gas cylinder 1 and the pipeline and are not released from the fuel supply system 100, so that the dispersed gas is not released, and the sealing performance and the safety performance of the CNGV fuel supply system 100 for storing the low-temperature LNG and the high-pressure CNG are improved.

A third valve body 31 is arranged between the normal-temperature high-pressure gas cylinder 3 and the gas using end 4, and the third valve body 31 can control the communication between the normal-temperature high-pressure gas cylinder 3 and the gas using end 4. When the third valve 31 controls the normal-temperature high-pressure gas cylinder 3 to be communicated with the gas using end 4, the gaseous natural gas in the normal-temperature high-pressure gas cylinder 3 can be guided to the gas using end 4, the gas using end 4 is processed and then used by an engine, and when the third valve 31 controls the normal-temperature high-pressure gas cylinder 3 to be disconnected from the gas using end 4, the gaseous natural gas is limited in the normal-temperature high-pressure gas cylinder 3 and a pipeline, the fuel supply system 100 cannot release diffused gas, and the sealing performance and the safety of the fuel supply system 100 are improved.

The first valve body 21, the second valve body 51 and the third valve body 31 can selectively communicate the gas end 4 with the normal-temperature high-pressure gas cylinder 3 and the low-temperature high-pressure gas cylinder 1 respectively when in use, and are isolated from the outside when the fuel supply system 100 is not used when a vehicle is shut down, so that the release of bleed gas is avoided, and the safety of the fuel supply system 100 is ensured.

Specifically, as shown in fig. 1, the first valve body 21, the second valve body 51, and the third valve body 31 are all hydraulically-controlled one-way valves.

First valve body 21 is the automatically controlled check valve of hydraulic pressure, and when using, through the automatically controlled check valve of signal of telecommunication control hydraulic pressure, the automatically controlled check valve of hydraulic pressure is reverse conducting state, and gaseous state natural gas accessible first valve body 21 is followed low temperature high pressure gas cylinder 1 and is used gas end 4 in the direction, but can not follow and use gas end 4 backward flow to low temperature high pressure gas cylinder 1, avoids the backward flow. When the gas supply system is not used, the gas supply system is normally switched off to be a hydraulic electric control one-way valve, a passage from the low-temperature high-pressure gas cylinder 1 to the gas using end 4 can be cut off, the gaseous natural gas cannot be guided from the low-temperature high-pressure gas cylinder 1 to the gas using end 4 through the first valve body 21, the fuel supply system 100 cannot release diffused gas, and the sealing performance and the safety performance of the fuel supply system 100 are improved. Similarly, the second valve body 51 and the third valve body 31 can also deliver fuel to the gas end 4 when being controlled, and are in a cut-off state when not being controlled, which is not described herein.

By adopting the hydraulic electric control one-way valve, the fuel supply system 100 is conducted when the hydraulic electric control one-way valve is controlled, the low-temperature high-pressure gas cylinder 1 and the normal-temperature high-pressure gas cylinder 3 can be sealed when the hydraulic electric control one-way valve is not controlled, the fuel supply system 100 can not release the diffused gas, and the sealing property and the safety of the fuel supply system 100 are improved. The hydraulic electrically-controlled check valve is convenient to use, and when the vehicle engine is shut down, the control of the hydraulic electrically-controlled check valve is automatically stopped, so that the fuel supply system 100 is stably closed. And the control is convenient, the control energy is directly cut off when the engine is shut down, the response is rapid and stable when the fuel supply system 100 is closed, the automatic realization can be realized, and the operation is safe and convenient.

In some embodiments, as shown in fig. 1 and 2, the fuel supply system 100 for a vehicle further includes: the gas-liquid separation device comprises a liquid injection pipe 6 and an exhaust pipe 7, wherein one end of the liquid injection pipe 6 is connected with the other end of a liquid filling pipe 5, the liquid injection pipe 6 is used for filling liquefied natural gas into the low-temperature high-pressure gas cylinder 1, and a fourth valve body 61 is arranged on the liquid injection pipe 6; one end of the air exhaust pipe 7 is connected with the other end of the air return pipe 2, the air exhaust pipe 7 is used for exhausting residual air in the low-temperature high-pressure air bottle 1, and the air exhaust pipe 7 is provided with a fifth valve body 71; when the liquid injection pipe 6 and the air extraction pipe 7 are used for filling fuel, residual air in the low-temperature high-pressure gas cylinder 1 can be discharged, so that the low-temperature high-pressure gas cylinder 1 can be smoothly filled with the fuel, and the fourth valve body 61 and the fifth valve body 71 are both mechanical controllable one-way valves.

One end of the liquid injection pipe 6 is connected with the other end of the liquid filling pipe 5, and the other end of the liquid injection pipe 6 is connected with a liquid adding device of a liquid adding station and used for filling liquefied natural gas into the low-temperature high-pressure gas cylinder 1. The fourth valve body 61 is arranged on the liquid injection pipe 6, so that the liquid injection pipe 6 can be communicated with a liquid adding device when liquid natural gas is required to be filled in the low-temperature high-pressure gas cylinder 1, the fuel supply system 100 can be separated from the outside when the low-temperature high-pressure gas cylinder 1 is not filled with the liquid natural gas, a closed system is formed, the diffused gas cannot be released, and the sealing performance and the safety of the fuel supply system 100 are improved.

One end of the exhaust tube 7 is selectively connected with the other end of the air return tube 2, and the other end of the exhaust tube 7 is connected with an air extractor of the liquid adding station and used for extracting residual air from the low-temperature high-pressure gas bottle 1. The fifth valve 71 is arranged on the exhaust pipe 7, so that the low-temperature high-pressure gas cylinder 1 can be communicated with an exhaust device when residual gas needs to be pumped out of the low-temperature high-pressure gas cylinder 1, and the fuel supply system 100 can be separated from the outside after the low-temperature high-pressure gas cylinder 1 is filled with liquefied natural gas, so that a closed system is formed, no diffused gas can be released, and the closure and the safety of the fuel supply system 100 are improved.

In some particular embodiments of the present application, the CNGV fuel supply system 100 storing cryogenic LNG and high-pressure CNG further comprises: the gas injection pipe, the one end of gas injection pipe is optional links to each other with muffler 2, also is provided with the valve body on the gas injection pipe. It can be understood that the low-temperature high-pressure gas pressure valve is used for storing low-temperature liquefied natural gas and gaseous natural gas, so that the low-temperature high-pressure gas cylinder 1 can be filled with not only liquefied natural gas but also gaseous natural gas, during the running process of a vehicle, if the fuel in the fuel supply system 100 is insufficient, and no filling station near the running of the vehicle can be used for supplement, the gaseous natural gas can be filled into the low-temperature high-pressure gas cylinder 1 for transitional use, and the functionality of the fuel supply system 100 can be improved.

According to the fuel supply system 100 of the embodiment of the application, by arranging the first valve body 21, the second valve body 51, the third valve body 31, the fourth valve body 61 and the fifth valve body 71, the low-temperature high-pressure gas cylinder 1 can be completely closed after a vehicle is filled with fuel, and the discharge of diffused gas is avoided; when the engine is flamed out and is powered off, the fuel supply passage can automatically close the electric control hydraulic electric control one-way valve, so that the low-temperature high-pressure gas cylinder 1 and the normal-temperature high-pressure gas cylinder 3 are sealed, and the exhaust of scattered gas is avoided; when the vehicle stops, the fuel supply passage can be automatically closed, the low-temperature high-pressure gas cylinder 1 and the normal-temperature high-pressure gas cylinder 3 are sealed, the exhaust and the emission gas are avoided, even if the liquefied natural gas is completely vaporized into the gaseous natural gas, the gas cylinder can not be failed, the sealing performance and the safety of the fuel supply system 100 are improved, and the vehicle using the embodiment can be safely parked in a garage.

Optionally, as shown in fig. 1 and fig. 2, an overflow valve 22 is provided between the normal-temperature high-pressure gas cylinder 3 and the other end of the muffler 2, and the overflow valve 22 can control the connection and disconnection between the low-temperature high-pressure gas cylinder 1 and the normal-temperature high-pressure gas cylinder 3. In some embodiments of the present application, when the pressure value reaches 5MPa, the overflow valve 22 is automatically opened, and the gaseous natural gas can be shunted into the normal-temperature high-pressure gas cylinder 3.

In some embodiments, as shown in fig. 1 and 2, the gas-using end 4 comprises: the low-temperature high-pressure gas cylinder comprises a first heat exchanger 41, a first pressure reducer 42, a second heat exchanger 43 and a second pressure reducer 44, wherein one end of the low-temperature high-pressure gas cylinder 1 is selectively communicated with a heat exchange pipe in the first heat exchanger 41, and the heat exchange pipe in the first heat exchanger 41 is communicated with the first pressure reducer 42. One end of the normal-temperature high-pressure gas cylinder 3 is selectively communicated with a heat exchange tube in the second heat exchanger 43, and the heat exchange tube in the second heat exchanger 43 is communicated with the second pressure reducer 44.

Specifically, the first heat exchanger 41 and the second heat exchanger 43 are evaporators, the first heat exchanger 41 can heat and raise the temperature of the liquefied natural gas and the gaseous natural gas in the low-temperature high-pressure gas cylinder 1, and convert the fuel into the gaseous normal-temperature natural gas, and the second heat exchanger 43 can heat and raise the temperature of the low-temperature gaseous natural gas in the normal-temperature high-pressure gas cylinder 3. First decompressor 42 and first heat exchanger 41 intercommunication can step down the gaseous state natural gas after rising the temperature, supplies with gas end 4 and supplies the engine to burn usefulness, and second decompressor 44 and second heat exchanger 43 intercommunication can step down the gaseous state natural gas after rising the temperature, supply with gas end 4 and supply the engine to burn usefulness.

In some embodiments of the present application, the liquefied natural gas and the gaseous natural gas in the low-temperature high-pressure gas cylinder 1 are both converted into normal-temperature natural gas after being heated, and then are depressurized to 0.8MPa by the first pressure reducer 42 for combustion by the engine; the low-temperature gaseous natural gas in the normal-temperature high-pressure gas cylinder 3 is converted into normal-temperature natural gas after being heated, and then is decompressed to 0.8MPa by the second decompressor 44 for combustion of the engine.

In some other embodiments of the present application, the liquefied natural gas filled in the cryogenic high-pressure gas cylinder 1 may be preheated, so that the fuel can be quickly used by the engine.

In some specific embodiments of the present application, as shown in fig. 5 and 6, the CNGV fuel supply system 100 storing cryogenic LNG and high-pressure CNG of embodiments of the present application further includes a simplified version. The fuel supply system 100 includes: the gas-natural gas guiding device comprises a third heat exchanger 45 and a third pressure reducer 46, one end of the low-temperature high-pressure gas cylinder 1 is communicated with a heat exchange tube in the third heat exchanger 45, the heat exchange tube in the third heat exchanger 45 is communicated with an overflow valve 22, the overflow valve 22 is connected with the normal-temperature high-pressure gas cylinder 3, the third pressure reducer 46 is connected with the other end of the normal-temperature high-pressure gas cylinder 3, the gas-natural gas in the normal-temperature high-pressure gas cylinder 3 is guided to a gas using end 4, a third valve body 31 is arranged between the normal-temperature high-pressure gas cylinder 3 and the gas using end 4, and the third valve body 31 can control the communication between the normal-temperature high-pressure gas cylinder 3 and the gas using end 4.

The third heat exchanger 45 is an evaporator, the third heat exchanger 45 can heat and heat the liquefied natural gas and the gaseous natural gas in the low-temperature high-pressure gas cylinder, and can convert the fuel into the gaseous normal-temperature natural gas, the gaseous normal-temperature natural gas can flow into the normal-temperature high-pressure gas cylinder 3 through the overflow valve 22, the third pressure reducer 46 is communicated with the normal-temperature high-pressure gas cylinder 3, and can depressurize the heated gaseous natural gas and supply the gas end 4 for combustion of the engine. The simplified version of the CNGV fuel supply system 100 storing low-temperature LNG and high-pressure CNG of the present application can reduce the number of hydraulic electrically-controlled check valves, and can also reduce the number of heat exchangers and pressure reducers, thereby reducing the cost of the fuel supply system again.

The structure and use of the CNGV fuel supply system 100 storing cryogenic LNG and high-pressure CNG of one embodiment will be described in detail below.

The fuel supply system 100 includes: the gas cylinder comprises a low-temperature high-pressure gas cylinder 1, a gas return pipe 2, a liquid filling pipe 5, a normal-temperature high-pressure gas cylinder 3 and a gas using end 4, wherein the low-temperature high-pressure gas cylinder 1 adopts a 65-liter seamless container capable of bearing the use temperature of minus 162 ℃ and the bearing pressure of 35MPa, and the normal-temperature high-pressure gas cylinder 3 adopts a 35-liter seamless container with the bearing pressure of 35 MPa. The low-temperature high-pressure gas cylinder 1 is provided with a first opening 11 and a second opening 12, one end of the gas return pipe 2 extends into the low-temperature high-pressure gas cylinder 1 through the first opening 11, the normal-temperature high-pressure gas cylinder 3 is connected with the other end of the gas return pipe 2 to receive compressed natural gas generated when the low-temperature high-pressure gas cylinder 1 is heated, one end of the liquid filling pipe 5 extends into the low-temperature high-pressure gas cylinder 1 through the second opening 12, the other end of the liquid filling pipe 5 is selectively communicated with the gas using end 4, the other end of the gas return pipe 2 is selectively communicated with the gas using end 4, and one end, which is not connected with the gas return pipe 2, of the normal-temperature high-pressure gas cylinder 3 is selectively communicated with the gas using end 4. Wherein, the end of the liquid charging pipe 5 extending into the low-temperature high-pressure gas cylinder 1 is positioned at the lower side of the end of the gas return pipe 2 extending into the low-temperature high-pressure gas cylinder 1. The gas end 4 comprises: the low-temperature high-pressure gas cylinder comprises a first heat exchanger 41, a first pressure reducer 42, a second heat exchanger 43 and a second pressure reducer 44, wherein one end of the low-temperature high-pressure gas cylinder 1 is selectively communicated with a heat exchange pipe in the first heat exchanger 41, and the heat exchange pipe in the first heat exchanger 41 is communicated with the first pressure reducer 42. One end of the normal-temperature high-pressure gas cylinder 3 is selectively communicated with a heat exchange tube in the second heat exchanger 43, and the heat exchange tube in the second heat exchanger 43 is communicated with the second pressure reducer 44.

A first valve body 21 is arranged between the other end of the gas return pipe 2 and the gas using end 4, a second valve body 51 is arranged between the other end of the liquid charging pipe 5 and the gas using end 4, and the first valve body 21 and the second valve body 51 can control the communication between the low-temperature high-pressure gas cylinder 1 and the gas return end. A third valve body 31 is arranged between the normal-temperature high-pressure gas cylinder 3 and the gas using end 4, and the third valve body 31 can control the communication between the normal-temperature high-pressure gas cylinder 3 and the gas using end 4. The first valve body 21, the second valve body 51 and the third valve body 31 are all hydraulically-controlled one-way valves. The fuel supply system 100 further includes: annotate liquid pipe 6 and exhaust tube 7, the one end of annotating liquid pipe 6 links to each other with the other end of liquid charging pipe 5, and the other end of annotating liquid pipe 6 links to each other with the liquid feeding device at liquid feeding station, be used for filling liquid natural gas to low temperature high pressure gas cylinder 1, be provided with fourth valve body 61 on annotating liquid pipe 6, the one end of exhaust tube 7 links to each other with the other end of muffler 2, and the other end of exhaust tube 7 can be used for linking to each other with the air exhaust device at liquid feeding station, exhaust tube 7 is used for discharging the residual gas in the low temperature high pressure gas cylinder 1, be provided with fifth valve body 71 on the exhaust tube 7. An overflow valve 22 is arranged between the normal-temperature high-pressure gas cylinder 3 and the other end of the muffler 2, and the overflow valve 22 can control the connection and disconnection between the low-temperature high-pressure gas cylinder 1 and the normal-temperature high-pressure gas cylinder 3.

When the liquid natural gas filling device is used, when the low-temperature high-pressure gas cylinder 1 is filled with liquid natural gas, the fourth valve body 61 is firstly opened to connect a household device of a liquid adding station with a liquid adding pipe, and the liquid natural gas filling device is used for filling the liquid natural gas into the low-temperature high-pressure gas cylinder 1. The liquid filling pipe 5 is connected with the liquid filling pipe 6 to fill the low-temperature high-pressure gas cylinder 1 with the liquefied natural gas, but at the initial filling stage of the liquefied natural gas, the liquefied natural gas is still at room temperature, the liquefied natural gas boils to generate the gaseous natural gas, and the gaseous natural gas possibly remains in the low-temperature high-pressure gas cylinder 1 for complete use, so that the saturated air pressure in the low-temperature high-pressure gas cylinder 1 can be gradually increased, and when the air pressure in the low-temperature high-pressure gas cylinder 1 exceeds the filling pressure of the liquid filling station, the liquefied natural gas cannot be filled. Two mechanical one-way valves are arranged in a liquid filling gun in a liquid filling station and are simultaneously connected with a liquid filling pipe 5 and an air return pipe 2, liquid natural gas is filled into a low-temperature high-pressure gas cylinder 1, simultaneously, residual gas of gaseous natural gas is pumped out through the air return pipe 2, the residual gas pressure is consumed to be below 4Mpa, the filling speed of the liquid natural gas is accelerated, 35-standard-square natural gas can be filled into the low-temperature high-pressure gas cylinder 1, after filling is finished, a fourth valve body 61 is closed, the low-temperature high-pressure gas cylinder 1 is sealed, and discharging and bleeding are avoided. The liquefied natural gas is gradually vaporized after being filled into the low-temperature high-pressure gas cylinder 1, a gas-liquid mixed state is formed in the low-temperature high-pressure gas cylinder 1, when the pressure value reaches 5MPa, the overflow valve 22 is automatically opened, and the gaseous natural gas can be shunted and enter the normal-temperature high-pressure gas cylinder 3.

When the vehicle is traveling, the first valve element 21, the second valve element 51, and the third valve element 31 are controlled to guide the fuel to the gas-using end 4. When the first valve body 21 controls the gas return pipe 2 to be communicated with the gas using end 4, the gaseous natural gas in the low-temperature high-pressure gas cylinder 1 can be guided to the gas using end 4, the first heat exchanger 41 can heat and heat the gaseous natural gas in the low-temperature high-pressure gas cylinder 1, and the fuel is converted into gaseous high-temperature natural gas, and then the gaseous high-temperature natural gas is subjected to pressure reduction to 0.8MPa through the first pressure reducer 42 and is supplied to an engine for combustion; when the second valve body 51 controls the liquid charging pipe 5 to be communicated with the gas using end 4, the liquefied natural gas in the low-temperature high-pressure gas cylinder 1 can be guided to the gas using end 4, the liquefied natural gas in the low-temperature high-pressure gas cylinder 1 can be heated and heated by the first heat exchanger 41, and the fuel is converted into gaseous high-temperature natural gas, and then the gaseous high-temperature natural gas is subjected to pressure reduction to 0.8MPa by the first pressure reducer 42 and is supplied to an engine for combustion; when the third valve body 31 controls the normal-temperature high-pressure gas cylinder 3 to be communicated with the gas using end 4, the gaseous natural gas in the normal-temperature high-pressure gas cylinder 3 can be guided to the gas using end 4, the gaseous natural gas in the normal-temperature high-pressure gas cylinder 3 is converted into high-temperature natural gas after being heated, and then the gaseous natural gas is decompressed to 0.8MPa through the second decompressor 44 to be used for burning of the engine.

When the engine of the vehicle is turned off or the vehicle stops and is placed in a garage, the control of the electrically-controlled hydraulic electrically-controlled one-way valve is automatically stopped, the conduction of the first valve body 21, the second valve body 51 and the third valve body 31 is closed, the fuel supply system 100 is stably closed, the low-temperature high-pressure gas cylinder 1 and the normal-temperature high-pressure gas cylinder 3 are closed, and the emission of scattered gas is avoided.

Other constructions of the fuel supply system 100 according to the embodiment of the present application, such as the evaporator and the pressure reducer, etc., and operations thereof, are known to those of ordinary skill in the art and will not be described in detail herein.

In the description herein, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims

1. A CNGV fuel supply system for storing cryogenic LNG and high pressure CNG, comprising:

a cryogenic high pressure gas cylinder having a first opening;

one end of the air return pipe extends into the upper side of the inner cavity of the low-temperature high-pressure gas cylinder through the first opening;

the normal-temperature high-pressure gas cylinder is connected with the other end of the gas return pipe to receive compressed natural gas generated after the low-temperature high-pressure gas cylinder is vaporized;

and the gas using end is selectively communicated with the normal-temperature high-pressure gas cylinder and the low-temperature high-pressure gas cylinder respectively.

2. The CNGV fuel supply system for storing cryogenic LNG and high pressure CNG according to claim 1, further comprising: one end of the liquid filling pipe extends into the lower side of the inner cavity of the low-temperature high-pressure gas cylinder through the first opening, and the other end of the liquid filling pipe is selectively communicated with the gas using end.

3. The CNGV fuel supply system for storing cryogenic LNG and high pressure CNG as claimed in claim 1, wherein the cryogenic high pressure gas cylinder further has a second opening, the CNGV fuel supply system for storing cryogenic LNG and high pressure CNG further comprising: one end of the liquid filling pipe extends into the lower side of the inner cavity of the low-temperature high-pressure gas cylinder through the second opening, and the other end of the liquid filling pipe is selectively communicated with the gas using end.

4. A CNGV fuel supply system for storing cryogenic LNG and high-pressure CNG according to claim 2 or 3, wherein a first valve is provided between the other end of the gas return pipe and the gas end, a second valve is provided between the other end of the liquid charging pipe and the gas end, and a third valve is provided between the normal-temperature and high-pressure gas cylinder and the gas end.

5. The CNGV fuel supply system for storing cryogenic LNG and high-pressure CNG according to claim 4, wherein the first, second and third valve bodies are all hydraulically-controlled one-way valves.

6. The CNGV fuel supply system for storing cryogenic LNG and high-pressure CNG according to claim 2 or 3, further comprising: the gas-liquid separation device comprises a liquid injection pipe and an exhaust pipe, wherein one end of the liquid injection pipe is connected with the other end of the liquid filling pipe, the liquid injection pipe is used for filling liquid natural gas into the low-temperature high-pressure gas cylinder, and a fourth valve body is arranged on the liquid injection pipe; one end of the air exhaust pipe is connected with the other end of the air return pipe, the air exhaust pipe is used for exhausting residual air in the low-temperature high-pressure air bottle, and a fifth valve body is arranged on the air exhaust pipe; the liquid injection pipe and the air exhaust pipe can exhaust residual gas in the low-temperature high-pressure gas cylinder when used for filling fuel, so that the low-temperature high-pressure gas cylinder can smoothly fill the fuel, and the fourth valve body and the fifth valve body are both mechanical controllable one-way valves.

7. A CNGV fuel supply system for storing cryogenic LNG and high pressure CNG as claimed in claim 1, wherein an overflow valve is provided between the normal temperature and high pressure gas cylinder and the other end of the return pipe to ensure that only vaporized natural gas can be introduced into the normal temperature and high pressure gas cylinder.

8. The CNGV fuel supply system for storing cryogenic LNG and high-pressure CNG according to claim 1, wherein the gas end comprises:

the low-temperature high-pressure gas cylinder is communicated with a heat exchange tube in the first heat exchanger in a selectable mode, and the heat exchange tube in the first heat exchanger is communicated with the first pressure reducer;

the heat exchange tube in the second heat exchanger is communicated with the second pressure reducer.

9. The CNGV fuel supply system for storing low-temperature LNG and high-pressure CNG according to claim 1, wherein the pressure in the low-temperature high-pressure gas cylinder is always below 35MPa by additionally arranging the normal-temperature high-pressure gas cylinder and shunting gaseous natural gas, so that the requirement on high-pressure safety of the gas cylinder is reduced.

10. A CNGV fuel supply system for storing cryogenic LNG and high-pressure CNG as claimed in claim 1, wherein the storage time of cryogenic fuel can be reduced by adding the normal-temperature high-pressure gas cylinder, and the requirement for low-temperature heat insulation of the gas cylinder is reduced.

11. A CNGV fuel supply system for storing cryogenic LNG and high-pressure CNG according to claim 1, wherein it is unnecessary to use a material having high pressure resistance and a material having high thermal insulation to manufacture the cryogenic high-pressure gas cylinder, thereby reducing the manufacturing cost thereof.