CN111623230A

CN111623230A - Low-temperature high-pressure gas cylinder capable of directly filling LNG and avoiding blow-off BOG

Info

Publication number: CN111623230A
Application number: CN202010560003.6A
Authority: CN
Inventors: 王义官; 洪讵
Original assignee: Zigong Tongda Machinery Manufacturing Co ltd
Current assignee: Zigong Tongda Machinery Manufacturing Co ltd
Priority date: 2020-06-18
Filing date: 2020-06-18
Publication date: 2020-09-04

Abstract

The invention discloses a low-temperature high-pressure gas cylinder capable of directly filling LNG and avoiding BOG (boil off gas), which consists of a high-pressure gas cylinder resistant to minus 162 ℃ and a shell protective layer, is a three-type high-pressure aluminum cylinder or steel cylinder with a cold insulation layer and carbon fibers cured by low-temperature resin, can store LNG for a long time to form a gas-liquid two-phase coexisting state, can supply low-pressure gas to an engine for a long time, is internally provided with a CNG (compressed natural gas) return pipe and an LNG liquid filling pipe, can ensure that low-pressure LNG is smoothly filled from an LNG liquid filling station, is provided with an electrically controlled stop valve at an inlet of an evaporator, can ensure that the gas cylinder forms a closed system in a long-term non-gas state after an engine of a vehicle is shut off, is not provided with a valve for directly discharging atmosphere in the system. The low-temperature high-pressure gas cylinder replaces the current CNG high-pressure gas cylinder, so that the storage capacity of fuel can be increased, the driving range of a vehicle can reach 500 kilometers, the dependence of CNGV on a high-pressure gas station can be avoided, and LNG can be directly used.

Description

Low-temperature high-pressure gas cylinder capable of directly filling LNG and avoiding blow-off BOG

Technical Field

The invention relates to the field of natural gas storage and use, in particular to a low-temperature high-pressure gas cylinder capable of directly filling LNG and avoiding blow-off gas BOG.

Background

Natural gas is a promising clean petrochemical energy source for motor vehicles in the coming centuries. Along with the exploitation of a large amount of shale gas, the development and application of combustible ice and the scale popularization of HCNG, more natural gas resources are provided for motor vehicles, and the shale gas and the conventional natural gas are prepared into pure liquid fuel LNG, so that clean, cheap and convenient gaseous energy is provided for the motor vehicles, and the current situation of serious emission pollution of the fuel oil motor vehicles is fundamentally changed.

Liquefied Natural Gas (LNG) is the most ideal clean fuel for various natural gas vehicles and is widely used in various large vehicles (LNGV) because of its advantages of pure quality, safe use, high energy density, more stored fuels, short filling time, high filling efficiency, etc.

Due to the disturbance of the bleed gas BOG, LNG can only be used for large-scale, long-distance and open-air parked vehicles at present, but also can not be used for medium and small-scale vehicles. National regulations mandate that LNG be stored and used at the following sites: vehicles with an engine displacement of less than 2 liters, fuel liquid storage vessels (dewars) with a volume of less than 150 liters, and natural gas vehicles parked in closed garages.

Most (over 90%) natural gas vehicles are also only able to use and store compressed natural gas CNG as fuel. CNG of 20MPa is required to be filled from a CNG filling station or an LNG vaporization station. Although no gas leaks, the method can only be used for short-distance operation around the urban center due to low storage density and short driving range. The above-mentioned drawbacks can be overcome only by increasing the pressure of the gas cylinder for vehicles. It is effective to increase the cylinder pressure from the current 20MPa to 30-35 MPa: the driving range of the small passenger car can be increased to more than 300 kilometers. However, increasing the storage pressure increases the gas cylinder cost and the investment and energy consumption of the gas station; especially, when the pressure is increased to more than 35MPa, the cost for inflating and storing the gas of the vehicle is greatly increased.

If the small passenger car can be directly filled with LNG as fuel, the small passenger car will be a subversive change: on one hand, the emission is clean, and the use is convenient like using gasoline; on the other hand, LNG has substantially the same calorific value as fuel (still slightly higher than gasoline), and the price is only 70% of that of gasoline, which can save 30% of the cost.

Then, the dependence of a natural gas vehicle on a pipeline gas filling station can be eliminated, and LNG can be directly filled from a liquid storage tank of the liquid natural gas filling station, so that the method is convenient and low in cost; is environment-friendly and safe; has great benefit to individuals and countries, and has wide application prospect.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, an object of the present invention is to provide a low-temperature high-pressure gas cylinder capable of directly filling LNG and eliminating BOG in the purge gas, which can be filled with natural gas in a liquid state, can maintain a gas-liquid coexisting state, and does not release BOG.

The low-temperature high-pressure gas cylinder capable of directly filling LNG and avoiding BOG (boil off gas) of the diffused gas mainly comprises the following components: an inner bottle made of 304 or 316 stainless steel or 6061 aluminum alloy capable of withstanding a use temperature of-196 ℃ into a seamless container; the inner bottle volume V is suitable for filling or storing a first volume V1 of low-temperature liquid natural gas and a second volume V2 of gaseous natural gas, and the first volume V1 of low-temperature liquid natural gas stored in the high-pressure inner bottle is suitable for endothermic conversion into gaseous natural gas; the efficient prestress winding layer is formed by winding resin-impregnated high-strength carbon fibers T700 capable of bearing the use temperature of-196 ℃ on the whole outer surface of an inner bottle in a tension mode with a preset rated value, the efficient prestress winding layer and the inner bottle are combined to form a high-pressure inner bottle, the high-pressure inner bottle jointly bears design pressure under no-load conditions, full-load conditions and any harsh combination conditions, namely the high-pressure inner bottle jointly bears low-temperature liquid natural gas with the maximum filling coefficient V1/V of less than or equal to 0.9 stored in the inner bottle, the high-pressure inner bottle has the maximum working pressure Pmax when the high-pressure inner bottle absorbs heat and is completely converted into gaseous natural gas, and the working pressure Pmax and the working temperature are jointly used as load conditions; the outer shell protective layer is made of common stainless steel or nonmetal, an installation space is formed in the outer shell protective layer, the high-pressure inner bottle is fixed in the installation space, and a spacing space is formed between the high-pressure inner bottle and the outer shell protective layer.

According to the low-temperature high-pressure gas cylinder capable of directly filling LNG and avoiding BOG (boil off gas) of the diffused gas, the seamless container is made of 304 or 316 stainless steel or 6061 aluminum alloy capable of bearing the use temperature of 196 ℃ below zero, the high-strength carbon fiber T700 capable of bearing the use temperature of 196 ℃ below zero is impregnated with resin, and the high-pressure inner cylinder is formed by winding all outer surfaces of the inner cylinder with the tension of a preset rated value, so that the high-pressure inner cylinder can be filled with and store the liquid natural gas, and the high-pressure inner cylinder can keep a gas-liquid coexisting state, and therefore the driving mileage of vehicles such as automobiles can be increased.

Further, through the shell protective layer that sets up, install the bottle in the shell protective layer with the high pressure to make and be formed with the interval space between bottle and the shell protective layer in the high pressure, can keep apart bottle and external environment in the high pressure to a certain extent, thereby can install under the prerequisite of bottle in not damaging the high pressure, also reduce the installation condition of low temperature high-pressure gas cylinder easily, thereby reduce installation cost, still be difficult for bringing frostbite operating personnel's potential safety hazard.

In addition, the low-temperature high-pressure gas cylinder according to the invention can also have the following additional technical characteristics:

in some embodiments of the present invention, the space is adapted to be evacuated to a vacuum state or a rough vacuum state, which plays a main role in heat insulation; the low-temperature high-pressure gas cylinder further comprises: the heat insulation protective layer is suitable for being filled in the space and blocking heat exchange between the high-pressure inner bottle and the outside air, and meanwhile, the workload of vacuumizing is reduced. Or the heat insulation protective layer is not arranged, and a heat source is introduced into the space to heat the LNG in the bottle.

In some embodiments of the present invention, both ends of the low temperature and high pressure gas cylinder are respectively provided with a first opening and a second opening communicating with the inside of the inner cylinder, and the low temperature and high pressure gas cylinder further includes: liquid feeding pipe and muffler, the liquid feeding pipe with the muffler set up in first opening with in at least one of second opening, liquefied natural gas is suitable for the follow the liquid feeding pipe adds in the interior bottle, when through the liquid feeding pipe to when interior bottle filling liquefied natural gas, the muffler is suitable for and the recovery unit intercommunication, in order to make things convenient for to interior bottle is filling liquefied natural gas smoothly, in the interior bottle liquefied natural gas with in the low temperature high pressure gas bottle gaseous state natural gas be suitable for from the liquid feeding pipe with the muffler flows out, in order to supply with the engine and use.

In some embodiments of the invention, the cryogenic high pressure gas cylinder further comprises: the first group of one-way valves comprise one-way valves arranged on connecting channels of the liquid adding pipe, the air return pipe and the LNG liquid adding station, so that the low-temperature high-pressure gas cylinder keeps an absolute sealing state when liquid is not added, and BOG is not released; and the second group of one-way valves comprise one-way valves arranged on connecting channels of the liquid adding pipe, the air return pipe and the engine, so that the low-temperature high-pressure gas cylinder is kept in an absolute sealing state when the engine is shut down, and BOG cannot be released.

In some embodiments of the present invention, the high-pressure inner cylinder and the outer shell protection layer are both formed in an oblong shape with similar contours to form the oblong low-temperature high-pressure gas cylinder, the oblong low-temperature high-pressure gas cylinder is suitable for being laid horizontally, one end of the low-temperature high-pressure gas cylinder is suitable for being penetrated by a liquid feeding pipe and an air return pipe, the liquid feeding pipe is suitable for extending downwards along the inner wall surface of the high-pressure inner cylinder after extending into the high-pressure inner cylinder, and the air return pipe is suitable for extending upwards along the inner wall surface of the high-pressure inner cylinder after extending into the high-pressure inner cylinder.

In some embodiments of the present invention, the low-temperature and high-pressure gas cylinder further includes a heater, at least a portion of the heater is adapted to extend into the high-pressure inner cylinder, and the heater extends along an extending direction of an inner wall surface of the high-pressure inner cylinder after extending into the high-pressure inner cylinder, so as to heat the liquefied natural gas in the high-pressure inner cylinder, or the heater includes a heating pipe, the heating pipe is formed into a U-shaped pipe, a heat conducting medium is adapted to be introduced into the U-shaped pipe, and at least a portion of the U-shaped heating pipe is adapted to extend into the high-pressure inner cylinder.

In some embodiments of the present invention, the high-pressure inner cylinder and the outer shell protection layer are each formed in an oblong shape with a similar contour to form the oblong low-temperature high-pressure gas cylinder, the oblong low-temperature high-pressure gas cylinder is adapted to be placed vertically, the liquid feeding pipe is adapted to extend into the inner cylinder from a lower end of the low-temperature high-pressure gas cylinder, the gas return pipe is adapted to extend into the inner cylinder from an upper end of the low-temperature high-pressure gas cylinder, or the liquid feeding pipe and the gas return pipe are both adapted to extend into the inner cylinder from an upper end of the low-temperature high-pressure gas cylinder, and a lowest point of the liquid feeding pipe is lower than a lowest point of the.

In some embodiments of the invention, the low-temperature high-pressure gas cylinder further comprises an external belt type evaporation device, the external belt type evaporation device is arranged between the high-pressure inner cylinder and the engine, the liquid natural gas and the gaseous natural gas in the high-pressure inner cylinder are suitable for flowing to the external belt type evaporation device from the liquid feeding pipe and the gas return pipe, and the normal-temperature natural gas heated by the external belt type evaporation device is suitable for being directly supplied to the engine.

In some embodiments of the invention, the limit pressure that the high-pressure inner bottle can withstand is defined as a first pressure Pa 1: 35 to 56.25 MPa.

In some embodiments of the invention, the temperature T of the liquefied natural gas charged into the cryogenic high-pressure gas cylinder is defined as: -82.3 ℃ to-162 ℃.

Additional aspects and advantages of the invention 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 invention.

Drawings

The above and/or additional aspects and advantages of the present invention 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 diagram of a horizontal cryogenic high pressure cylinder according to an embodiment of the invention;

FIG. 2 is a schematic view of the structure in the direction A of FIG. 1;

FIG. 3 is a schematic view of the structure in the direction B of FIG. 1;

fig. 4 is a schematic structural view of a filling pipe and a gas return pipe of the vertical cryogenic high-pressure gas cylinder according to the embodiment of the invention;

FIG. 5 is a schematic structural diagram of another filling pipe and air return pipe of the vertical cryogenic high-pressure gas cylinder according to the embodiment of the invention;

FIG. 6 is a schematic diagram of a horizontal cryogenic high-pressure cylinder in cooperation with an external band evaporator according to an embodiment of the invention;

fig. 7 is a schematic structural diagram of the vertical type low-temperature high-pressure gas cylinder matched with the external belt type evaporator according to the embodiment of the invention.

Reference numerals:

100: a low temperature high pressure gas cylinder;

1: a first bottle cap; 2: a heater; 3: a housing protective layer; 4: a glass fiber protective layer; 5: a carbon fiber reinforcement layer; 6: an inner bottle; 7: a liquid feeding pipe; 8: an air return pipe; 9: a second bottle cap; 10: a one-way valve; 11: an intervening space; 12: an external belt type evaporation plant; 13: a heat-conducting inlet; 14: a heat conduction outlet.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, 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 accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

A cryogenic high pressure gas cylinder 100 capable of directly filling LNG and precluding blow-off BOG according to an embodiment of the present invention is described below with reference to fig. 1 to 7. Here, NG is an english abbreviation of normal natural gas, LNG is an english abbreviation of liquid natural gas, CNG is an english abbreviation of gaseous natural gas, and BOG is an english abbreviation of dispersed gas.

Referring to fig. 1 to 7, a cryogenic high-pressure gas cylinder 100 capable of directly filling LNG and preventing blow-off BOG according to an embodiment of the present invention mainly includes an inner cylinder 6, an effective pre-stress winding layer, and an outer shell protective layer 3.

Specifically, the inner bottle 6 is made of 304 or 316 stainless steel or 6061 aluminum alloy which can bear the use temperature of-196 ℃ to be a seamless container; the inner bottle 6 has a volume V and is suitable for filling or storing a first volume V1 of low-temperature liquid natural gas and a second volume V2 of gaseous natural gas, the first volume V1 of low-temperature liquid natural gas stored in the high-pressure inner bottle is suitable for absorbing heat and converting the low-temperature liquid natural gas into the gaseous natural gas, the effective prestress winding layer adopts resin impregnated high-strength carbon fiber T700 which can bear the use temperature of-196 ℃, the high-pressure natural gas bottle is formed by winding all the outer surfaces of the inner bottle 6 with preset rated value tension, the effective prestress winding layer and the inner bottle 6 are combined to form the high-pressure inner bottle, the high-pressure inner bottle bears the design pressure under no-load condition, full-load condition and any harsh combination condition together, the high-pressure inner bottle bears the low-temperature natural gas with the maximum filling coefficient V1/V less than or equal to 0.9 stored in the inner bottle 6 together, and has a maximum working pressure Pmax, together with the working temperature, as the load condition, when endothermically completely converted to gaseous natural gas. The high-pressure inner bottle can be designed according to pressure explosion tests, pressure fatigue tests, drop tests, burning tests, gun-striking tests, corrosion resistance tests and the like.

For the above technical solution, the following can be understood:

according to the working principle of the LNG-CNG vaporizing station, a certain amount of LNG is filled in the vehicle low-temperature high-pressure gas cylinder 100, enough heat is absorbed, the LNG can be vaporized and prepared into CNG with set pressure, and the CNG is stored in the low-temperature high-pressure gas cylinder 100 and continuously used by an engine, so that the driving mileage of an automobile can be increased.

Further, the first volume V1 of the cryogenic liquefied natural gas filled in the high-pressure inner bottle satisfies: V1/V is less than or equal to 0.9, when the liquefied natural gas of the first volume V1 absorbs heat and is completely converted into the gaseous natural gas, the gaseous natural gas in the high-pressure inner bottle generates the maximum working pressure Pmax, and the inner bottle 6 formed by 304 or 316 stainless steel or 6061 aluminum alloy is matched with the effective prestress winding layer, so that the bearing pressure P of the high-pressure inner bottle can meet the following requirements: p is more than or equal to Pmax.

Further, the liquid LNG absorbs heat and is vaporized to produce gaseous CNG. The more the heat absorbed, the more the CNG produced, and finally, the CNG is completely vaporized into gaseous CNG. When LNG is completely vaporized, the volume of the LNG is expanded by 625 times (the LNG can be expanded to 625 cubic meters of normal pressure natural gas NG after vaporization every 1 cubic meter of LNG), therefore, compared with the low-temperature high-pressure gas cylinder 100 of the natural gas automobile in the prior art, the LNG automobile can only be filled or stored with gaseous natural gas, which easily causes the problems of short driving distance, continuous natural gas filling and the like, the low-temperature liquid natural gas can be directly filled in the high-pressure inner cylinder of the LNG automobile, the liquid natural gas can be filled and stored in the high-pressure inner cylinder through the materials adopted by the high-pressure inner cylinder, the matching mode of the inner cylinder 6 and the effective prestress winding layer, and the filling coefficient, at the moment, the gas-liquid coexisting state is kept in the high-pressure inner cylinder, and the LNG can be expanded to 625 cubic meters of normal pressure natural gas NG after vaporization every 1 cubic meter of LNG, so that the liquid natural gas can, the high-pressure inner bottle can automatically convert the liquid natural gas in the high-pressure inner bottle into the gaseous natural gas to be loaded on vehicles such as automobiles, so that the requirement of taking the gaseous fuel gas can be met, and the driving mileage of the vehicles such as automobiles can be greatly increased.

Further, the atmospheric natural gas NG which can expand to 625 cubic meters per 1 cubic meter of LNG vaporized can generate an internal pressure of 62.5Mpa if the system is closed, and the maximum pressure value of CNG generated by LNG vaporization in the low-temperature high-pressure gas cylinder 100 depends only on the LNG capacity initially charged in the low-temperature high-pressure gas cylinder 100, in other words, the LNG capacity is large, the maximum working pressure Pmax in the high-pressure inner cylinder is high, the LNG capacity is small, and the maximum working pressure Pmax in the high-pressure inner cylinder is low. It should be noted that the first volume V1 in the present application is only indicated as the maximum storage volume of the liquefied natural gas, and in practical applications, the volume of the liquefied natural gas to be filled may be smaller than the first volume V1, and is not limited specifically.

Further, a Boil Off Gas (BOG) is an inevitable phenomenon in a low-temperature and low-pressure vessel in which LNG is stored, because in a gas-liquid coexisting vessel, as external heat is introduced and the saturation pressure of a gas phase is gradually increased, when the gas pressure reaches a certain value, a valve is opened to be released into the surrounding atmosphere, and the released gas is called BOG. BOG is a fuel gas loss, causes environmental pollution, and causes secondary disasters such as ignition, combustion, explosion and the like due to dangerous concentration. And therefore must be disposed of in the storage vessel for the LNG.

At present, the method for treating BOG collects the discharged dispersed gas for utilization, or pressurizes the gas to form high-pressure compressed natural gas CNG, or cools the gas to form low-temperature liquid natural gas LNG. LNG filling stations and LNG storage tanks must be equipped with such recovery devices, and some scattered occasions (such as running LNGV vehicles or scattered LNG containers) have difficulty in achieving recovery, so that the country has made strict regulations restricting the use of LNG containers (the core of which is to avoid the scattering of BOG). Such as: the volume of the storage container is not less than 150L, the vehicle is used in a spacious place, an open air and a smooth air circulation producing area, and when the storage container is applied to a small-sized vehicle, BOG and the engine displacement are not allowed to be lower than 2L. And the bottle in the high pressure of this application does not establish gas release valve, and the in-process also does not have the gas to leak, as long as the bottle does not appear breaking in the high pressure, and the gas just can not leak.

Further, low temperature high pressure gas cylinder 100 of this application still includes shell protective layer 3, shell protective layer 3 can be made by ordinary stainless steel or nonmetal, be formed with installation space in the shell protective layer 3, the bottle is fixed in installation space in the high pressure, and be formed with interval space 11 between bottle and the shell protective layer 3 in the high pressure, it can be understood here, because the interior storage of bottle has low temperature liquefied natural gas in the high pressure, make the temperature of the outer wall of bottle also in the low temperature state in the high pressure easily, the outer wall of bottle in the high pressure of low temperature state, increase the installation degree of difficulty and the installation cost on the car easily, and simultaneously, avoid the low temperature outer wall to become the potential safety hazard, the frostbite contacter. From this, through the shell protective layer 3 that sets up, install the bottle in the high pressure in shell protective layer 3 to make and be formed with interval space 11 between bottle and the shell protective layer 3 in the high pressure, can keep apart bottle and external environment in the high pressure to a certain extent, thereby can install under the prerequisite of bottle in not haring the high pressure, also reduce low temperature high pressure gas cylinder 100's installation condition easily, thereby reduce installation cost, still be difficult for bringing frostbite operating personnel's potential safety hazard.

The materials of the inner bottle 6, the effective pre-stressed winding layer and the outer shell protection layer 3 can be replaced by those skilled in the art according to the actual application, and are not limited herein. In a specific example, the inner bottle 6 can be made of other types of austenitic materials, or other alloy materials, besides 304 or 316 stainless steel or 6061 aluminum alloy. Besides adopting low-temperature resin to impregnate the high-strength carbon fiber T700, the effective prestress winding layer can also adopt a protection method in the conventional technology that a carbon fiber reinforced layer 5 and a glass fiber protective layer 4 are arranged on the outer side of the low-temperature high-pressure gas cylinder 100 or the carbon fiber reinforced layer 5 and the glass fiber protective layer 4 are combined.

Therefore, according to the low-temperature high-pressure gas cylinder 100 capable of directly filling LNG and preventing the blow-off BOG, the seamless container is made of 304 or 316 stainless steel or 6061 aluminum alloy capable of bearing the use temperature of 196 ℃ below zero, the high-strength carbon fiber T700 capable of bearing the use temperature of 196 ℃ below zero is impregnated with resin, and the high-pressure inner cylinder is formed by winding the high-pressure inner cylinder 6 at a preset fixed value in tension, so that the high-pressure inner cylinder can be filled with and store liquid natural gas, and the high-pressure inner cylinder can be kept in a gas-liquid coexisting state, and therefore, the driving mileage of vehicles such as automobiles can be increased. Further, through the shell protective layer 3 that sets up, install the bottle in the high pressure in shell protective layer 3 to make and be formed with interval space 11 in the high pressure between bottle and the shell protective layer 3, can keep apart the bottle and external environment in the high pressure to a certain extent, thereby can install under the prerequisite of bottle in not damaging the high pressure, also reduce low temperature high pressure gas cylinder 100's installation condition easily, thereby reduce installation cost, still be difficult for bringing the potential safety hazard.

In the above technical solution of the present invention, in order to further enhance the heat insulation protection capability of the high-pressure inner bottle, a certain treatment may be performed on the spacing space 11, specifically: in one example, the space 11 is adapted to be evacuated to a vacuum state or a rough vacuum state for thermal insulation; in another example, the cryogenic high pressure gas cylinder 100 further comprises: the heat insulation protective layer is suitable for being filled in the space 11 and is suitable for blocking heat exchange between the high-pressure inner bottle and the outside air, and meanwhile, the workload of vacuumizing is reduced. As another example, the heat source may be introduced into the space 11 without providing the heat insulating protective layer to accelerate heating of the LNG in the bottle, thereby increasing the amount of air supplied to the engine.

According to the scheme of the two examples, the heat insulation protection capability of the high-pressure inner bottle can be further improved, on one hand, the heat insulation protection capability of the high-pressure inner bottle is improved, the high-pressure inner bottle can be kept in a gas-liquid coexisting state for a long time, and therefore the high-pressure inner bottle is favorable for storing liquefied natural gas and using natural gas by an automobile, on the other hand, the heat insulation protection capability of the high-pressure inner bottle is improved, and potential safety hazards can be further reduced.

In some embodiments of the present invention, as shown in fig. 1, the cryogenic high-pressure gas cylinder 100 is provided with a first opening and a second opening at two ends thereof, respectively, which are communicated with the inside of the inner cylinder 6, and the cryogenic high-pressure gas cylinder 100 further comprises a first bottle cap 1 and a second bottle cap 9, wherein the first bottle cap 1 and the second bottle cap 9 are adapted to close the first opening and the second opening, respectively. The low-temperature high-pressure gas cylinder 100 further comprises a liquid adding pipe 7 and an air return pipe 8, the liquid adding pipe 7 and the air return pipe 8 are arranged in at least one of the first opening and the second opening, the liquefied natural gas is suitable for being added into the inner cylinder 6 from the liquid adding pipe 7, when the liquefied natural gas is filled into the inner cylinder 6 through the liquid adding pipe 7, the air return pipe 8 is suitable for being communicated with a recovery device, the liquefied natural gas is conveniently and smoothly filled into the inner cylinder 6, the liquefied natural gas in the inner cylinder 6 and the gaseous natural gas in the low-temperature high-pressure gas cylinder 100 are suitable for flowing out from the liquid adding pipe 7 and the air return pipe 8, and the low-temperature.

That is to say, can set up liquid feeding pipe 7 and muffler 8 in first opening simultaneously, also can set up liquid feeding pipe 7 and muffler 8 in the second opening simultaneously, can also set up liquid feeding pipe 7 in first opening, muffler 8 sets up in the second opening, in a specific example, recovery unit can establish on the liquid filling rifle to 100 filling liquefied natural gas of low temperature high pressure gas cylinder, and at this moment, the liquid feeding rifle is when filling liquefied natural gas towards 100 filling liquefied natural gas of low temperature high pressure gas cylinder, can directly take out the gaseous natural gas in the bottle, thereby conveniently annotate liquefied natural gas.

Further, the low-temperature high-pressure gas cylinder 100 further comprises a first group of one-way valves 10, the first group of one-way valves 10 comprise one-way valves 10 arranged on connecting channels of the liquid adding pipe 7, the air return pipe 8 and the LNG liquid adding station, so that the low-temperature high-pressure gas cylinder 100 keeps an absolute sealing state when liquid is not added, and BOG cannot be released, therefore, the low-temperature high-pressure gas cylinder 100 can be guaranteed not to release BOG when liquid natural gas is added into the low-temperature high-pressure gas cylinder 100 through the first group of one-way valves 10.

Furthermore, the low-temperature high-pressure gas cylinder 100 further comprises a second group of check valves 10, and the second group of check valves 10 comprises check valves 10 arranged on connecting channels of the charging pipe 7, the return pipe 8 and the engine, so that the low-temperature high-pressure gas cylinder 100 also keeps an absolute sealing state when the engine is shut down, and therefore the BOG cannot be released, and therefore, the low-temperature high-pressure gas cylinder 100 can also ensure that the BOG cannot be released when the engine is shut down through the second group of check valves 10.

Therefore, according to the first one-way valve 10 and the second one-way valve 10, the automobile can not generate diffused air in the processes of air filling and using, and relevant regulations of the state in the process of using the automobile can be met. Even in vehicles that are parked for extended periods of time, the LNG is totally vaporized and the pressure, although it reaches a maximum, does not exceed the design strength of the cylinder. No BOG is generated due to the provision of the check valve 10. The small LNG passenger vehicle can be parked in the closed garage.

The low-temperature high-pressure gas cylinder 100 can be horizontal and vertical according to the placement requirements, the horizontal mode refers to the placement in the left-right direction as shown in fig. 1, and the liquid adding pipe 7 and the gas return pipe 8 need to be arranged in some mode in order to meet the requirements of natural gas injection and natural gas use after the horizontal mode and the vertical mode of the low-temperature high-pressure gas cylinder 100 are placed.

In some embodiments of the invention, the high pressure inner bottle and the outer shell protector 3 are each formed in a similarly contoured oblong shape, so as to form an oblong low-temperature high-pressure gas cylinder 100, the oblong low-temperature high-pressure gas cylinder 100 is suitable for being horizontally laid down, so as to be suitable for being placed in a trunk or the like of a small-sized automobile, in one example as shown in fig. 1, one end of the cryogenic high-pressure gas cylinder 100 is adapted to be penetrated by a filling tube 7 and a gas return tube 8, the filling tube 7 is adapted to extend downward along the inner wall surface of the high-pressure inner cylinder after extending into the high-pressure inner cylinder, the gas return tube 8 is adapted to extend upward along the inner wall surface of the high-pressure inner cylinder after extending into the high-pressure inner cylinder, thereby, the gaseous natural gas can be well recovered when the liquid natural gas is filled, the difficulty of filling the liquid natural gas can be reduced, and moreover, when the natural gas in the high-pressure inner bottle is taken out, the natural gas can flow out from the gas return pipe 8 to be conveyed towards the engine.

In other embodiments of the present invention, as shown in fig. 4 and 5, the high-pressure inner cylinder and the outer shell protective layer 3 are each formed in an oblong shape with a similar contour to form an oblong low-temperature high-pressure gas cylinder 100, and the oblong low-temperature high-pressure gas cylinder 100 is adapted to be placed vertically, which means in the up-down direction. In the example shown in fig. 4, the filling pipe 7 is adapted to extend from the lower end of the low-temperature high-pressure gas cylinder 100 into the inner cylinder 6, and the gas return pipe 8 is adapted to extend from the upper end of the low-temperature high-pressure gas cylinder 100 into the inner cylinder 6, or, in the example shown in fig. 5, both the filling pipe 7 and the gas return pipe 8 are adapted to extend from the upper end of the low-temperature high-pressure gas cylinder 100 into the inner cylinder 6, and the lowest point of the filling pipe 7 is lower than the lowest point of the gas return pipe 8, so that the gaseous natural gas can be better recovered when filling the liquefied natural gas, the difficulty of filling the liquefied natural gas can be reduced, and when taking the natural gas in the high-pressure inner cylinder, the natural gas can flow out from the.

In some embodiments of the present invention, the present application may heat the gaseous natural gas in order to facilitate the supply of the gaseous natural gas to the engine due to considerations of the use of the gaseous natural gas in the cryogenic high pressure gas cylinder 100.

Specifically, the method comprises the following steps: referring to the schematic structural diagrams of the separated space 11 shown in fig. 6 and 7 and referring to the schematic structural diagram of the heating in the separated space 11 shown in fig. 4 as the first embodiment: the both ends of the length direction of shell protective layer 3 are formed with heat conduction import 13 and heat conduction export 14, and heat conduction import 13 all communicates with clearance space 11 with heat conduction export 14, and heat-conducting medium is suitable for and gets into clearance space 11 from heat conduction import 13 to the liquefied natural gas heating in the bottle in the high pressure for liquefied natural gas converts gaseous natural gas into with higher speed, and heat-conducting medium in the clearance space 11 is suitable for and flows out from heat conduction export 14.

That is to say, in the process of preserving the natural gas at low temperature high pressure gas cylinder 100, can carry out thermal-insulated of certain degree through compartment space 11, in order to reduce the heat exchange, prolong liquefied natural gas's save time, and when the natural gas in low temperature high pressure gas cylinder 100 is used to needs, because the endothermic speed can be to the speed that liquefied natural gas turned into gaseous natural gas, and, there is the difference between the pressure and the temperature of the natural gas of conventional state and gaseous natural gas, consequently, carry out the mode of heating through leading-in heat-conducting medium in compartment space 11, can improve the speed that liquefied natural gas turned into gaseous natural gas, also can satisfy the quantity of the natural gas that the engine used to a certain extent, or reduce in the follow-up process, turn into the degree of difficulty that can supply the engine to use.

Referring to fig. 1 and 5, the structure of heating in a high-pressure inner bottle is schematically shown as example two: the low-temperature high-pressure gas cylinder 100 further includes a heater 2, as shown in fig. 1, at least a portion of the heater 2 is adapted to extend into the high-pressure inner cylinder, and after the heater 2 extends into the high-pressure inner cylinder, the heater 2 extends along an extending direction of an inner wall surface of the high-pressure inner cylinder to heat the liquefied natural gas in the high-pressure inner cylinder, or, as shown in fig. 5, the heater 2 includes a heating pipe, the heating pipe is formed into a U-shaped pipe, a heat-conducting medium is adapted to be introduced into the U-shaped pipe, and at least a portion of the U-shaped heating pipe is adapted to extend.

That is to say, through the mode that heats the natural gas in the bottle in the high pressure, improve the speed that liquefied natural gas turns into gaseous natural gas, also can satisfy the quantity of the natural gas that the engine used to a certain extent, perhaps reduce follow-up in-process, turn into the degree of difficulty that can supply the conventional natural gas that the engine used with gaseous natural gas.

Referring to fig. 6 and 7, the third embodiment shows a schematic structural diagram of heating outside the cryogenic high-pressure gas cylinder 100: the low-temperature high-pressure gas cylinder 100 further comprises an outer belt type evaporation device 12, the outer belt type evaporation device 12 is arranged between the high-pressure inner cylinder and the engine, the liquefied natural gas and the gaseous natural gas in the high-pressure inner cylinder are suitable for flowing to the outer belt type evaporation device 12 from the liquid feeding pipe 7 and the gas return pipe 8, and the normal-temperature natural gas heated by the outer belt type evaporation device 12 is suitable for being directly supplied to the engine.

That is, the natural gas output from the high-pressure inner bottle is heated to meet the standard of the natural gas used by the engine, where the natural gas output from the high-pressure inner bottle may be a gaseous natural gas or a liquid natural gas, and is not limited herein.

As for the third embodiment, there may be a fourth specific embodiment, referring to fig. 6, the low-temperature high-pressure gas cylinder 100 is placed horizontally, the two ends of the low-temperature high-pressure gas cylinder 100 are respectively provided with a liquid inlet pipe and an air return pipe 8, and the liquid inlet pipe and the air return pipe 8 are respectively connected to the pipeline of the gas station and the pipeline connected to the external belt type evaporation device 12 and are respectively provided with a check valve 10, where the check valve 10 may be a common check valve or an electronic check valve, further, the natural gas output by the low-temperature high-pressure gas cylinder 100 towards the external belt type evaporation device 12 may be gaseous natural gas or liquid natural gas, and further, the low-temperature high-pressure gas cylinder 100 may simultaneously output natural gas towards the external belt type evaporation device 12 through the liquid feeding pipe 7 and the air return pipe 8.

As for the third embodiment, there may be a fifth specific embodiment, referring to fig. 7, the low-temperature high-pressure gas cylinder 100 is placed vertically, two ends of the low-temperature high-pressure gas cylinder 100 are respectively provided with a liquid inlet pipe and an air return pipe 8, and the liquid inlet pipe and the air return pipe 8 are respectively connected to a pipeline of the gas station and a pipeline connected to the external belt type evaporation device 12 and are respectively provided with a check valve 10, where the check valve 10 may be a mechanical check valve 10 or an electronic check valve 10, further, the natural gas output by the low-temperature high-pressure gas cylinder 100 towards the external belt type evaporation device 12 may be a gaseous natural gas or a liquid natural gas, and further, the low-temperature high-pressure gas cylinder 100 may simultaneously output the natural gas towards the external belt type evaporation device 12 through the liquid inlet pipe 7 and the air return pipe 8.

As can be seen from the first to third embodiments, the gas cylinder 100 may be heated in the cylinder, the space 11, and the outside of the gas cylinder 100, but it is understood that any combination of the first, second, and third embodiments may be performed according to actual use requirements, and the present application is not limited thereto.

During the specific design process of the present application, according to "1 m³The liquid LNG can be completely vaporized to generate 625m³According to the principle of gaseous NG, the volume (or weight) of LNG which needs to be filled into the low-temperature high-pressure gas cylinder 100 in a limited amount can be accurately calculated according to the conditions of the pressure-bearing capacity, the volume, the ambient temperature and the like of the low-temperature high-pressure gas cylinder 100, so that the highest pressure of the generated CNG is controlled, and the safety of the low-temperature high-pressure gas cylinder 100 is ensured. In order to meet the requirement of driving the automobile at 500KM, according to the hundred-kilometer gas average consumption data of the small-sized natural gas passenger vehicle, (7NM3/100KM or 5.02kg/100KM), the following data can be calculated: the cryogenic high pressure gas cylinder 100 must be filled with 56 liters (or 25.1 kilograms) of liquefied natural gas.

For example: in a cryogenic high-pressure gas cylinder 100 with a volume of 62L, which only allows 90% of the LNG volume to be filled, i.e. only allows 55.8LLNG to be filled, the highest pressure that can be generated by the cryogenic high-pressure gas cylinder 100 is: p62.5 MpaX0.9 56.25 MPa.

For another example: 56L of LNG is charged into an 80L low-temperature high-pressure gas cylinder 100, and the maximum pressure that can be generated is 62.5MpaX56/80 Mpa 43.75 MPa.

The following steps are repeated: the maximum pressure P of 56X62.5/100 Mpa generated by charging 56L of LNG into 100L of low-temperature high-pressure gas cylinder 100 is 35 Mpa.

Accordingly, it can be seen that: by determining the strength of the low-temperature high-pressure gas cylinder 100, the maximum pressure ultimately generated by the low-temperature high-pressure gas cylinder 100 can be controlled by controlling the filling amount of LNG. As long as the volume and the pressure-bearing level of the low-temperature high-pressure gas cylinder 100 are determined, the LNG charge amount can be accurately calculated.

The larger the LNG weight ratio (or volume ratio) charged in the low-temperature and high-pressure gas cylinder 100, the higher the pressure of the generated CNG. Regulations permit the cryogenic high pressure cylinder 100 to be charged to a maximum of 90% of its volume, and therefore the maximum pressure of CNG produced will not exceed 56.25 Mpa. The strength of the low-temperature high-pressure gas cylinder 100 can be designed according to the design.

Thus, in some examples of the invention, the limiting pressure that the high pressure inner bottle can withstand is defined as a first pressure Pa 1: 35-56.25 MPa to meet the use requirement of the low-temperature high-pressure gas cylinder 100.

Further, for the convenience of understanding the present application, the following description will be made in detail of the process of filling and converting the liquefied natural gas and the gaseous natural gas in the cryogenic high-pressure gas cylinder 100:

first, to meet the liquidity demand of natural gas, the temperature T of the liquefied natural gas charged into the low-temperature high-pressure gas cylinder 100 is defined as: -82.3 ℃ to-162 ℃.

At the moment of filling the LNG, since the low-temperature high-pressure gas cylinder 100 is still at room temperature, the LNG in the cylinder will boil rapidly, and the gas pressure in the cylinder will increase rapidly, so that the LNG cannot be filled normally (the existing LNG filling gun structure belongs to low-pressure filling), and the gas in the cylinder should be discharged in time, so as to ensure the normal filling of the LNG. And when the volume of the low-temperature high-pressure gas cylinder reaches 90 percent of the volume of the low-temperature high-pressure gas cylinder 100, the filling is finished. At the moment, the temperature and the pressure in the bottle tend to be stable, and the gas phase and the liquid phase are balanced.

First stage of conversion of liquefied natural gas into gaseous natural gas: LNG is heated, part of LNG is vaporized, and two phases of gas and liquid coexist. Specifically, at the initial stage of heat transfer, the LNG temperature rises, the CNG saturation pressure also rises, and finally the critical state is reached: the temperature is-82.3 ℃ and the low pressure is 4.23 MPa.

If the engine does not use fuel gas at this time, the gas phase and the liquid phase are kept in balance, the temperature and the pressure are kept unchanged, and the gas phase and the liquid phase are kept in balance. If the engine needs to use gas at this moment, a part of liquid-phase LNG absorbs heat and is vaporized into CNG: the amount of liquid phase is reduced and the amount of gas phase is increased for the engine.

When two phases coexist in the high-pressure inner bottle, the relationship between the LNG temperature and the CNG air pressure is as follows: as the temperature increases, the saturation pressure also increases, with a substantially positive correlation. From this, the heat Qlq (heat of vaporization of the liquid) required to vaporize the LNG to CNG at this stage can be estimated.

Specifically, knowing that the heat of vaporization of the LNG is 590KJ/Kg and the density of the LNG is 450Kg/NM3, the heat absorbed in the vaporization stage is calculated according to the LNG filling volume and the LNG filling weight by conversion: for example: in a 100L low-temperature high-pressure gas cylinder 100, 56L of LNG is filled, (CNG of 35Mpa can be formed) and the volume is converted into weight: g56 liters by 0.45 kg/liter 25.1 kg. The heat of vaporization required is then: qlq, 25.10KgX590, 590KJ/Kg, 14809, KJ, 4.11 KWH.

For another example: the 62L low-temperature high-pressure gas cylinder 100 is filled with 55.8L of LNG (90% of the volume of the low-temperature high-pressure gas cylinder 100 is filled, 56Mpa can be formed), and the weight of the filled LNG is converted into the following weight: g55.8 liters 0.45 kg/liter 25.11 kg. Then: the required vaporization amount Qlq is: qlq, 25.11KgX590, 590KJ/Kg, 14815, KJ, 4.115 KWH.

When two phases coexist in the high-pressure inner bottle, the relationship between the LNG temperature and the CNG air pressure is as follows: as the temperature increases, the saturation pressure also increases, with a substantially positive correlation. Thus, the heat required for the LNG temperature increase Qlw (heat of temperature increase of the liquid) at this stage is estimated:

the average specific heat of the LNG is 1.85 and the temperature rise is: -82.3- (-162) ═ 79.7 ℃, the weight of LNG in the cryogenic high pressure cylinder 100 is 25.1kg, and the liquid exotherm heat required at the temperature rise stage is: qlw-25.1-1.85-79.7-3682 KJ-1.023 KWH.

In conclusion, the first stage is a stage in which two phases of gas and liquid coexist, the temperature is kept at the critical temperature of-82.3 ℃ for a long time, and the pressure can be kept at 4.23MPa for a long time. If gas is supplied to the engine at this stage, the low-temperature high-pressure gas cylinder 100 needs to produce and supply gas on one hand, and can maintain the gas-liquid two-phase balance on the other hand. At this time, the temperature of the low-temperature high-pressure gas cylinder 100 is unchanged, and the output of the low-temperature high-pressure gas cylinder is 4.23Mpa low-temperature low-pressure CNG gas and LNG fuel liquid (still-82.3 ℃). The output gas and the fuel liquid can be changed into room temperature gas only by additional heating.

A second stage of conversion of the liquefied natural gas into gaseous natural gas: when the temperature is higher than the critical temperature, the low-temperature high-pressure gas cylinder 100 enters an LNG complete vaporization section, LNG is continuously vaporized along with heat transfer and at the beginning, the quantity of CNG is increased, the gas pressure is rapidly increased to reach the maximum value, and the temperature is still unchanged (-82.3 ℃). At this time, the liquid is no longer present, and the output is low-temperature and high-pressure fuel gas. Subsequently, the heat transfer is mainly used for heating the CNG gas from-82.3 ℃ to room temperature. The output is normal temperature and high pressure fuel gas.

The average specific heat (1.85) of CNG is found out from the data, and the heat quantity Qcw (heat of gas rise) required by CNG at this stage can be calculated according to the weight of CNG in the bottle and the temperature difference between before and after the CNG.

For example: filling 25.1kg LNG into a 100L low-temperature high-pressure gas cylinder 100, vaporizing to generate 35Mpa CNG, raising the critical temperature from-82.3 ℃ to 20 ℃ at room temperature, and heating: the weight-average specific heat capacity temperature rise of Qcw is 25.1, 1.85, 102.3, 4750KJ, 8451/3600, 1.32 KWH.

For another example: 25.11kgLNG is filled into a 62L low-temperature high-pressure gas cylinder 100, the LNG is vaporized to generate 56.25Mpa CNG, the temperature is increased from-82.3 ℃ to 20 ℃, and the temperature is required to be increased: (iv) Qcw-average specific heat capacity temperature rise 25.11-1.85-102.3-4752 KJ-1.32 KWH;

further, the present application analyzes the influence of the heating condition on the vaporization speed, and specifically, to meet the gas demand of the engine, the low-temperature and high-pressure gas cylinder 100 can be directly heated to provide enough heat quantity qtot (total vaporization heat quantity), wherein the heat quantity qtot is composed of three parts, namely liquid vaporization heat Qlq + liquid temperature rise heat Qlw + gaseous temperature rise heat Qcw.

Therefore, according to the calculation result, the following results can be obtained: total Q Qlq + Qlw + Qcw 4.11+1.023+ 1.32-6.453 KWH.

In order to ensure that the low-temperature high-pressure gas cylinder 100 can absorb 6.453KWH heat within five hours and prepare enough fuel gas for the engine, the first embodiment, the second embodiment and the third embodiment or any combination of the first embodiment, the second embodiment and the third embodiment can be adopted.

According to the low temperature and high pressure gas cylinder 100 of the present application, CNG prepared and outputted in the low temperature and high pressure gas cylinder 100 is different in different stages, and the states of the three cases are described specifically below.

The first condition is as follows: the gas phase and the liquid phase coexist at the critical temperature, the temperature is-82.3 ℃, the air pressure is 4.23Mpa, and low-temperature and low-pressure CNG and low-pressure LNG are output.

Case two: at the initial stage of the complete vaporization of LNG, the liquid phase does not exist, the temperature is-82.3 ℃, the pressure can reach the maximum value, and the output is low-temperature and high-pressure CNG.

The gas prepared in the two cases has low temperature, and is heated to room temperature in an evaporator and then sent to an engine. Otherwise the combustion efficiency of the engine is affected.

Case three: and in the stage of quickly rising the gas temperature, the temperature is close to the room temperature, and the output is the CNG with the normal temperature and the high pressure.

Obviously, the first case is ideal, which can save energy, and the strength load of the low-temperature high-pressure gas cylinder 100 is light. The low-pressure fuel gas should be prepared and stored in a two-phase coexistence stage as much as possible to obtain better effect and benefit.

The following description specifically describes the need to provide a sufficient amount of gas in coordination with the real-time gas usage of the engine, according to the cryogenic high-pressure gas cylinder 100 of the present application.

The air consumption of the engine is determined by actual working conditions and can be estimated according to the average air consumption of one hundred kilometers. (7nm3/100 km; 5.02kg/100km) low-temperature high-pressure gas cylinder 100 is required to provide a gas consumption of 25.1kg in five hours by heating which can be carried out in any combination of embodiment one, embodiment two and embodiment three, or embodiment one, embodiment two and embodiment three in the application. And the vaporization speed can be automatically adjusted through a temperature control system according to the real-time gas demand of the engine, so that the fuel gas can be economically prepared, and better economic benefit can be obtained. Therefore, the low-temperature high-pressure gas cylinder 100 should be equipped with a device for reading, recording and analyzing, judging and the like of state parameters such as temperature, gas pressure, time and the like, and form an automatic operation matched with an engine.

In order to accurately control the amount of supplied air to meet the demand of the engine, a simulation test should be performed season by season after the low-temperature and high-pressure gas cylinder 100 is successfully developed and for the specific situation of a small vehicle. Finally, the air consumption requirement of the engine is met with the least energy consumption.

In some embodiments of the present application, achieving accurate filling of a cryogenic high-pressure gas cylinder 100 with a fixed amount of LNG under cryogenic conditions is yet another key element in achieving the above-mentioned concept. The LNG flowmeter used in the current market can meet the metering requirement, the filling pressure of the liquid filling gun in the current market is not more than 2Mpa, and basically can meet the requirement, but the phenomenon of overhigh residual gas pressure caused by the boiling of LNG in the filling process is controlled. Since the low-temperature high-pressure gas cylinder 100 is at room temperature during filling and the LNG is at-162 ℃, the LNG may boil violently in the low-temperature high-pressure gas cylinder 100, causing a pressure rise, so that the low-temperature high-pressure gas cylinder 100 cannot be filled with LNG. The intelligent filling machine can automatically identify and detect parameters such as specification, capacity, temperature, residual gas pressure and the like of the low-temperature high-pressure gas cylinder 100 during filling, and automatic and accurate filling can be realized according to different conditions.

In some embodiments of the present application, in a critical state (82.3 ℃), low-pressure (4.23Mpa) natural gas can be drawn from the low-temperature high-pressure gas cylinder 100, connected to the external belt evaporator 12 for heating, and vaporized and warmed (by using the engine coolant) to become CNG at normal temperature and low pressure for the engine. Fig. 6 is a schematic diagram of the externally-hung external belt type evaporation device 12 of the horizontal low-temperature high-pressure gas cylinder 100, when the engine is shut down, the check valve 10 at the outlet of the low-temperature high-pressure gas cylinder 100 is automatically closed, and the fuel is sealed inside the low-temperature high-pressure gas cylinder 100. When the engine works, the low-pressure fuel in the low-temperature high-pressure gas cylinder 100 is pressed into the outer belt type evaporation device 12, is heated and vaporized, is heated and pressurized, and is supplied to the low-pressure or medium-pressure fuel gas of the engine. Fig. 7 shows a vertical low-temperature high-pressure gas cylinder 100 in which the externally-hung externally-mounted evaporation device 12 heats low-pressure LNG and CNG, the principle of which is completely the same as that of the horizontal low-temperature high-pressure gas cylinder 100, and the vertical low-temperature high-pressure gas cylinder 100 is suitable for being used in a trunk of a large-sized SUV vehicle with a large height, which is beneficial to smooth filling of LNG, rapid return of gas, and daily inspection and maintenance. The use is more convenient.

Other constructions and operations of the cryogenic high pressure gas cylinder 100 according to embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail herein.

In the description herein, references to the description of the terms "some embodiments," "optionally," "further," or "some examples," etc., mean 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 invention. 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 invention 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 invention, the scope of which is defined by the claims and their equivalents.

Claims

1. The utility model provides a can directly fill LNG and stop low temperature high pressure gas cylinder of loose gassing BOG which characterized in that mainly includes:

an inner bottle which is made of 304 or 316 stainless steel or 6061 aluminum alloy capable of bearing the use temperature of-196 ℃ and is manufactured into a seamless container; the inner bottle volume V is suitable for filling or storing a first volume V1 of low-temperature liquid natural gas and a second volume V2 of gaseous natural gas, and the first volume V1 of low-temperature liquid natural gas stored in the high-pressure inner bottle is suitable for endothermic conversion into gaseous natural gas;

the efficient prestress winding layer is formed by winding resin-impregnated high-strength carbon fibers T700 capable of bearing the use temperature of-196 ℃ on the whole outer surface of an inner bottle in a tension mode with a preset rated value, the efficient prestress winding layer and the inner bottle are combined to form a high-pressure inner bottle, the high-pressure inner bottle jointly bears design pressure under no-load conditions, full-load conditions and any harsh combination conditions, namely the high-pressure inner bottle jointly bears low-temperature liquid natural gas with the maximum filling coefficient V1/V of less than or equal to 0.9 stored in the inner bottle, the high-pressure inner bottle has the maximum working pressure Pmax when the high-pressure inner bottle absorbs heat and is completely converted into gaseous natural gas, and the working pressure Pmax and the working temperature are jointly used as load conditions;

the outer shell protective layer, the outer shell protective layer is made by ordinary stainless steel, be formed with installation space in the outer shell protective layer, the bottle is fixed in the high pressure in the installation space, just in the high pressure the bottle with be formed with the interval space between the outer shell protective layer.

2. The low-temperature high-pressure gas cylinder capable of being directly filled with LNG and avoiding BOG (boil-off gas) of the outgassing gas according to claim 1, wherein the space is suitable for being pumped into a vacuum state or a rough vacuum state to play a role in heat insulation; the low-temperature high-pressure gas cylinder further comprises: the heat insulation protective layer is suitable for being filled in the space and blocking heat exchange between the high-pressure inner bottle and the outside air, and meanwhile, the workload of vacuumizing is reduced.

3. The low-temperature high-pressure gas cylinder capable of directly filling LNG and preventing blow-off BOG according to claim 1, wherein a first opening and a second opening communicated with the inside of the inner cylinder are respectively arranged at two ends of the low-temperature high-pressure gas cylinder, and the low-temperature high-pressure gas cylinder further comprises:

liquid feeding pipe and muffler, the liquid feeding pipe with the muffler set up in first opening with in at least one of second opening, liquefied natural gas is suitable for the follow the liquid feeding pipe adds in the interior bottle, when through the liquid feeding pipe to when interior bottle filling liquefied natural gas, the muffler is suitable for and the recovery unit intercommunication, in order to make things convenient for to interior bottle is filling liquefied natural gas smoothly, in the interior bottle liquefied natural gas with in the low temperature high pressure gas bottle gaseous state natural gas be suitable for from the liquid feeding pipe with the muffler flows out, in order to supply with the engine and use.

4. The cryogenic high-pressure gas cylinder capable of being directly filled with LNG and precluding blow-off BOG according to claim 3, characterized by further comprising:

the first group of one-way valves comprise one-way valves arranged on connecting channels of the liquid adding pipe, the air return pipe and the LNG liquid adding station, so that the low-temperature high-pressure gas cylinder keeps an absolute sealing state when liquid is not added, and BOG is not released;

and the second group of one-way valves comprise one-way valves arranged on the connecting channels of the liquid feeding pipe, the air return pipe and the engine, so that the low-temperature high-pressure gas cylinder is kept in an absolute sealing state when the engine is shut down, and BOG cannot be released.

5. The low-temperature high-pressure gas cylinder capable of directly filling LNG and avoiding BOG (boil off gas) of the outgassing gas according to claim 3, wherein the high-pressure inner cylinder and the shell protective layer are both formed into oblong shapes with similar profiles so as to form the oblong low-temperature high-pressure gas cylinder, the oblong low-temperature high-pressure gas cylinder is suitable for being horizontally laid, one end of the low-temperature high-pressure gas cylinder is suitable for being provided with a liquid adding pipe and an air return pipe in a penetrating manner, the liquid adding pipe extends into the high-pressure inner cylinder and then is suitable for extending downwards along the inner wall surface of the high-pressure inner cylinder, and the air return pipe extends into the high-pressure inner cylinder and then is suitable for extending upwards along the inner wall.

6. The low-temperature high-pressure gas cylinder capable of directly filling LNG and avoiding BOG (boil off gas) of the outgassing gas according to claim 1, wherein the low-temperature high-pressure gas cylinder further comprises a heater, at least one part of the heater is suitable for extending into the high-pressure inner cylinder, and the heater extends into the high-pressure inner cylinder and then extends along the extending direction of the inner wall surface of the high-pressure inner cylinder so as to heat the liquefied natural gas in the high-pressure inner cylinder, or the heater comprises a heating pipe which is formed into a U-shaped pipe, a heat-conducting medium is suitable for being introduced into the U-shaped pipe, and at least one part of the U-shaped heating pipe is suitable for extending into the high-pressure inner cylinder.

7. The cylinder according to claim 3, wherein the high-pressure inner cylinder and the outer shell protective layer are formed in an oblong shape having a similar contour to form the oblong cylinder, the oblong cylinder is adapted to be placed vertically, the filling tube is adapted to extend into the inner cylinder from a lower end of the cylinder, and the return tube is adapted to extend into the inner cylinder from an upper end of the cylinder, or the filling tube and the return tube are adapted to extend into the inner cylinder from an upper end of the cylinder, and a lowest point of the filling tube is lower than a lowest point of the return tube.

8. The low-temperature high-pressure gas cylinder capable of directly filling LNG and avoiding BOG (boil off gas) of the outgassing gas according to claim 3, further comprising an external belt type evaporation device, wherein the external belt type evaporation device is arranged between the high-pressure inner cylinder and the engine, the liquefied natural gas and the gaseous natural gas in the high-pressure inner cylinder are suitable for flowing to the external belt type evaporation device from the liquid filling pipe and the gas return pipe, and the normal-temperature natural gas heated by the external belt type evaporation device is suitable for being directly supplied to the engine.

9. The cryogenic high-pressure gas cylinder capable of being directly filled with LNG and precluding blow-off BOG according to claim 1, characterized in that the limit pressure that the high-pressure inner cylinder can withstand is defined as a first pressure Pa 1: 35 to 56.25 MPa.

10. The cryogenic high-pressure gas cylinder capable of being directly filled with LNG and precluding boil-off gas BOG according to claim 1, wherein the temperature T of the liquefied natural gas filled in the cryogenic high-pressure gas cylinder is defined as: -82.3 ℃ to-162 ℃.