A vehicle-mounted natural gas system without pressure relief and emission and control method thereof

Abstract

The present invention discloses a vehicle-mounted natural gas system without pressure relief and emission and a control method thereof. The vehicle-mounted natural gas system includes an LNG energy storage tank and a bellows energy storage device connected to the LNG energy storage tank. The LNG energy storage tank includes several pressure relief ports connected to the bellows energy storage device. The bellows energy storage device includes a bellows energy storage chamber connected to the pressure relief port and an energy storage vaporization chamber connected to the bellows energy storage chamber. The gas in the bellows energy storage chamber can flow to the energy storage vaporization chamber so that the bellows energy storage chamber and the energy storage vaporization chamber maintain pressure balance. Therefore, the gas discharged from the pressure relief port of the LNG energy storage tank flows to the bellows energy storage device and will not be directly discharged into the atmosphere. The bellows energy storage device includes a bellows energy storage chamber connected to the pressure relief port and an energy storage vaporization chamber connected to the bellows energy storage chamber. The gas in the bellows energy storage chamber can flow to the energy storage vaporization chamber so that the bellows energy storage chamber and the energy storage vaporization chamber maintain pressure balance.

Description

Technical Field

[0001] The present invention belongs to the field of energy storage, and in particular relates to a vehicle-mounted natural gas system without pressure relief and emission and a control method thereof. Background Art

[0002] Cars that use LNG (Liquefied Natural Gas) as fuel have a series of advantages such as cleanliness, environmental protection, economy, long mileage, and low maintenance costs. However, the liquefied gas inside the LNG storage tank will be vaporized due to environmental factors, resulting in excessive pressure inside the LNG storage tank. Therefore, pressure relief and discharge are required. Currently, pressure relief and discharge are directly discharged into the atmosphere, which not only easily causes safety hazards, but also causes energy waste. Discharging into the atmosphere will also pollute the environment. Summary of the invention

[0003] In view of the above-mentioned deficiencies, the present invention provides a vehicle-mounted natural gas system without pressure relief and emission and a control method thereof, so as to prevent the pressure-relieved gas of the LNG energy storage tank from being directly discharged into the atmosphere.

[0004] The present invention is achieved through the following technical solutions:

[0005] A vehicle-mounted natural gas system without pressure relief and emission includes an LNG energy storage tank and a bellows energy accumulator connected to the LNG energy storage tank, the LNG energy storage tank includes a plurality of pressure relief ports connected to the bellows energy accumulator, the bellows energy accumulator includes a bellows energy storage chamber connected to the pressure relief ports and an energy storage vaporization chamber connected to the bellows energy storage chamber, the gas in the bellows energy storage chamber can flow to the energy storage vaporization chamber to keep the pressure balance between the bellows energy storage chamber and the energy storage vaporization chamber. Therefore, the gas discharged from the pressure relief port of the LNG energy storage tank flows into the bellows energy accumulator and will not be directly discharged into the atmosphere. The bellows energy accumulator includes a bellows energy storage chamber connected to the pressure relief port and an energy storage vaporization chamber connected to the bellows energy storage chamber. The gas in the bellows energy storage chamber can flow to the energy storage vaporization chamber to maintain pressure balance between the bellows energy storage chamber and the energy storage vaporization chamber. Among them, the gas discharged from the LNG energy storage tank enters the bellows energy storage chamber, and then enters the energy storage vaporization chamber from the bellows energy storage chamber, thereby ensuring that the bellows energy storage chamber and the energy storage vaporization chamber maintain pressure balance, avoiding pressure fluctuations, and thus playing a stabilizing role.

[0006] Furthermore, a corrugated elastic body is provided in the corrugated energy accumulator to separate the corrugated energy accumulator into a bellows energy storage chamber and an energy storage vaporization chamber, and the corrugated elastic body is located in the bellows energy storage chamber. The corrugated elastic body refers to a tubular elastic sensitive element formed by foldable corrugated sheets connected along the folding and stretching direction. The corrugated elastic body has a thinner wall and a higher sensitivity. When working, it stretches along the length direction of the elastic body under the action of internal pressure. The corrugated elastic body has good elasticity and high temperature resistance, so that the corrugated energy accumulator can be used under high temperature conditions.

[0007] Furthermore, the corrugated elastic body has several supports extending toward the inner wall of the corrugated energy accumulator, and the supports can slide along the inner wall of the corrugated energy accumulator. The supports at the corrugated elastic body can play a supporting role, thereby making the corrugated elastic body more stable as a whole. At the same time, when the supports move, they slide along the inner wall of the corrugated energy accumulator, and the friction between the supports and the corrugated energy accumulator is relatively small during sliding, thereby making the movement of the corrugated elastic body more convenient, and the reaction to pressure changes is more sensitive, and the pressure balance between the bellows energy storage chamber and the energy storage vaporization chamber is better ensured.

[0008] Furthermore, a one-way valve is provided at the connection between the bellows energy storage chamber and the energy storage vaporization chamber. The one-way valve allows the gas in the bellows energy storage chamber to flow to the energy storage vaporization chamber in one direction only, avoiding irregular pressure changes caused by gas backflow, which makes it difficult for the bellows energy storage chamber and the energy storage vaporization chamber to maintain pressure balance.

[0009] Furthermore, the pressure in the bellows energy storage chamber is not greater than 0.2MPA, and the pressure in the energy storage vaporization chamber is not greater than the pressure in the bellows energy storage chamber. The unvaporized liquefied gas entering the bellows energy storage chamber will stretch the bellows energy storage device after vaporization. After the internal pressure exceeds 0.2MPa, the one-way valve is opened, and the vaporized gas enters the gas storage chamber through the one-way valve. After the pressure in the energy storage vaporization chamber meets 0.2MPa, the bellows is compressed to the lower position, so that the pressure in the bellows energy storage chamber is balanced with the pressure in the energy storage vaporization chamber. When the system is supplying gas, the internal balance pressure is maintained at 0.2MPa. According to the calculation of the vaporization rate, the volume of the bellows energy storage device in this application meets the emission capacity requirement of vehicles parked for at least 6 months, and normal vehicles can meet the zero emission requirements.

[0010] Furthermore, the bellows energy storage device also includes a vacuum device disposed at the connection between the bellows energy storage chamber and the energy storage vaporization chamber. The vacuum device can realize vacuum processing in the middle of the bellows energy storage chamber, which can reduce the influence of the external high temperature environment on the internal air pressure.

[0011] Furthermore, the LNG energy storage tank includes a first pressure relief port and a second pressure relief port, and one of the first pressure relief port and the second pressure relief port is connected to the corrugated energy storage device. Pressure relief can be achieved through both the first pressure relief port and the second pressure relief port. When one of them fails, the other pressure relief port can be activated to relieve pressure, thereby better protecting the safety of the LNG energy storage tank.

[0012] Furthermore, the opening pressure at the first pressure relief port is lower than the opening pressure of the second pressure relief port. The opening pressure of the first pressure relief port is relatively small, so during the pressure relief process, the pressure is first relieved through the first pressure relief port, and the second pressure relief port is in a closed state. When the first pressure relief port fails, that is, the pressure reaches the opening pressure of the first pressure relief port, but the first pressure relief port does not open. At this time, the pressure will continue to rise until it reaches the opening pressure of the second pressure relief port. At this time, the pressure is relieved through the second pressure relief port, thereby ensuring that the pressure relief port can always be used to relieve pressure and protect the safety of the LNG energy storage tank.

[0013] Furthermore, a gas delivery device connected to the vehicle-mounted carburetor is provided at the energy storage vaporization chamber, and the vaporized gas in the energy storage vaporization chamber flows to the vehicle-mounted carburetor via the gas delivery device. Since the vehicle-mounted natural gas system of the present application is applied to the vehicle, the vaporized gas in the energy storage vaporization chamber can flow to the vehicle-mounted carburetor. Therefore, after the vehicle is started, the gas stored in the energy storage vaporization chamber flows to the vehicle-mounted carburetor, thereby providing fuel gas.

[0014] The present invention provides a vehicle-mounted natural gas control method without pressure relief emission, which is applied to the above-mentioned vehicle-mounted natural gas system. The control method includes:

[0015] S1: The LNG energy storage tank delivers gas to the bellows energy storage chamber of the bellows energy storage device through the pressure relief port, and gas is generated in the bellows energy storage chamber that can flow to the energy storage vaporization chamber;

[0016] S2: The gas in the bellows energy storage chamber can flow to the energy storage vaporization chamber, so that the pressure of the bellows energy storage chamber and the energy storage vaporization chamber is balanced;

[0017] S3: When the pressure in the energy storage vaporization chamber is greater than 0.45 MPa, the gas in the energy storage vaporization chamber is discharged to the vehicle-mounted vaporizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram for explaining a working principle of a schematic embodiment of the LNG energy storage tank and the corrugated energy storage device of the present invention;

[0019] Figure 2 A schematic structural diagram for illustrating a schematic implementation of the corrugated energy storage device of the present invention;

[0020] Figure 3 A schematic diagram of a three-dimensional structure for illustrating a schematic embodiment of the corrugated energy storage device of the present invention;

[0021] Figure 4 A schematic cross-sectional view for illustrating a schematic embodiment of the corrugated energy storage device of the present invention;

[0022] Figure 5 To illustrate Figure 4A local enlarged schematic diagram of point A in the middle.

[0023] Reference numerals:

[0024] 1. LNG energy storage tank, 2. Bellows energy storage device, 21. Bellows energy storage chamber, 22. Energy storage vaporization chamber, 23. Bellows elastic body, 24. Support, 25. Vacuum device, 26. Gas transmission device, 27. Pressure valve. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] It should be noted that the directional terms such as left, right, up, down, front and back in the embodiments of the present invention are merely relative concepts or are based on the normal use state of the product, that is, the direction of movement of the product, and should not be considered as limiting.

[0027] In addition, it should be noted that the dynamic terms such as "relative motion" mentioned in the embodiments of the present invention refer not only to changes in position, but also to movements such as rotation and rolling in which there is no relative change in position but a change in state.

[0028] Finally, it should be noted that when a component is referred to as being "located" or "set on" another component, it can be on the other component or there can be an intermediate component at the same time. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or there can be an intermediate component at the same time.

[0029] like Figures 1 to 5 A vehicle-mounted natural gas system without pressure relief and emission is shown, comprising an LNG energy storage tank 1 and a corrugated energy storage device 2 connected to the LNG energy storage tank 1, wherein the LNG energy storage tank 1 realizes the storage of LNG (Liquefied Natural Gas), which is vaporized into a gas of about 0.45MPa through a vaporization device and provided to the engine, and the pressure relief ports arranged at the LNG energy storage tank 1 all meet the discharge requirements. After one of the pressure relief ports fails, the remaining pressure relief ports can realize discharge, thereby protecting the safety of the LNG energy storage tank. However, in the existing pressure relief process, the gas is directly discharged into the atmosphere from the pressure relief ports, which not only poses a safety hazard, but also causes a waste of energy, and the discharge into the atmosphere will also pollute the environment.

[0030] When a vehicle equipped with the above-mentioned on-board natural gas system is driving, the liquefied gas in the LNG energy storage tank is vaporized under environmental factors, and the vaporized gas can be discharged through the pressure relief port, thereby ensuring the pressure stability in the LNG energy storage tank. It is understandable that the total amount of liquefied gas vaporized due to environmental factors is relatively small. Therefore, the present application sets a corrugated energy storage device to recycle the discharged naturally vaporized gas, thereby achieving safe discharge during pressure relief, thereby improving the safety of the vehicle during driving and parking, and avoiding environmental pollution.

[0031] It is understandable that the bellows accumulator targets the vaporization of liquefied gas under environmental factors, so the amount of liquefied gas collected and stored in the bellows accumulator is relatively small, and only the gas discharged during pressure relief is recovered and reused.

[0032] In the present application, the LNG energy storage tank 1 includes several pressure relief ports connected to the bellows energy accumulator 2, so that the gas discharged from the pressure relief ports of the LNG energy storage tank 1 flows into the bellows energy accumulator 2 and will not be directly discharged into the atmosphere. The bellows energy accumulator 2 includes a bellows energy storage chamber 21 connected to the pressure relief port and an energy storage vaporization chamber 22 connected to the bellows energy storage chamber 21. The gas in the bellows energy storage chamber 21 can flow to the energy storage vaporization chamber 22 to maintain pressure balance between the bellows energy storage chamber 21 and the energy storage vaporization chamber 22, wherein the gas discharged from the LNG energy storage tank 1 enters the bellows energy storage chamber 21, and then enters the energy storage vaporization chamber 22 from the bellows energy storage chamber 21, thereby ensuring that the bellows energy storage chamber 21 and the energy storage vaporization chamber 22 maintain pressure balance, avoiding pressure fluctuations, and thus playing a stabilizing role.

[0033] In the present application, the LNG energy storage tank 1 can transport gas to the corrugated energy accumulator 2, and the gas flows from the bellows energy storage chamber 21 to the energy storage vaporization chamber 22 in the corrugated energy accumulator 2. When the pressure in the energy storage vaporization chamber 22 is too high, it is necessary to discharge the gas in the energy storage vaporization chamber 22. Preferably, a gas transmission device 26 connected to the vehicle-mounted vaporizer is provided at the energy storage vaporization chamber 22, and the vaporized gas in the energy storage vaporization chamber 22 flows to the vehicle-mounted vaporizer through the gas transmission device 26; since the vehicle-mounted natural gas system of the present application is applied to the vehicle, the vaporized gas in the energy storage vaporization chamber 22 can flow to the vehicle-mounted vaporizer. Therefore, after the vehicle is started, the gas stored in the energy storage vaporization chamber 22 flows to the vehicle-mounted vaporizer, thereby providing fuel gas.

[0034] Preferably, a gas sensor is also provided in the bellows energy storage chamber 21, and the gas sensor can alarm when a gas leak occurs. When a gas leak alarm occurs in the bellows energy storage chamber 21, the structure in the bellows energy storage chamber 21 should be checked in time to see if it is damaged, thereby improving safety during use.

[0035] In the event of a gas leak, a portable methane detector can be used to check the natural gas leak point of the vehicle. To ensure the normal operation of the vehicle, system leak detection should be performed regularly, for example, using soap solution to check the leak point.

[0036] Preferably, the corrugated energy accumulator 2 also includes a pressure valve 27 for monitoring the pressure of the energy storage vaporization chamber 22; by setting the pressure valve 27, the pressure of the energy storage vaporization chamber 22 can be detected, thereby ensuring the safety of the energy storage vaporization chamber 22. In this embodiment, the safety pressure value of the energy storage vaporization chamber 22 is set to 0.45MPa, which can meet the pressure balance in the corrugated energy accumulator 2.

[0037] In the present application, a safety valve is also provided at the pressure valve. The safety valve is a leakage type safety valve using a spring servo. When the pressure in the energy storage vaporization chamber 22 is too high, that is, the pressure in the energy storage vaporization chamber 22 is greater than 0.45MPa, the gas in the energy storage vaporization chamber 22 will be automatically discharged from the safety valve, thereby ensuring that the pressure in the energy storage vaporization chamber is excessively high due to extreme conditions, thereby protecting the safety of the natural gas system as a whole. Among them, the vent pipe for automatic discharge is installed at the rear of the car, so as to be away from the cab and the passenger compartment, and safety can also be ensured.

[0038] In the present application, since the corrugated energy accumulator 2 stores gas, it needs to have a certain impact resistance and needs to reduce the impact of the external temperature on the inside of the corrugated energy accumulator 2. Therefore, the outer shell of the corrugated energy accumulator 2 in the present application is a double-layer structure, thereby reducing the impact of the external high temperature environment on the internal air pressure. Specifically, the corrugated energy accumulator 2 adopts a double-layer spherical shell, which has a strong resistance to external pressure impact strength; at the same time, the overall structure of the corrugated energy accumulator 2 is made of 304 stainless steel, thereby meeting the requirements of low-temperature performance; at the same time, the corrugated energy accumulator 2 is set to a double-layer structure, and the sealing performance is better. Even if the internal components are damaged, it will not cause material leakage.

[0039] Preferably, the bellows energy storage device 2 also includes a vacuum device 25 disposed at the connection between the bellows energy storage chamber 21 and the energy storage vaporization chamber 22; the vacuum device 25 can evacuate the middle part of the bellows energy storage chamber 21, and can also reduce the impact of the external high temperature environment on the internal air pressure.

[0040] In summary, in the present application, the cavity of the bellows energy accumulator is a sealed cavity, and the vacuum device 25 can evacuate the middle part of the bellows energy storage chamber 21, that is, evacuate the energy storage vaporization chamber, and the corrugated elastomer in the bellows energy storage chamber is a double-wall structure, which can reduce the impact of changes in the external environment on the bellows energy accumulator.

[0041] When the corrugated energy accumulator 2 is installed, the chassis of the corrugated energy accumulator 2 is installed as a whole with the chassis carrying the LNG energy storage tank 1 through the mounting flange, and the connection is connected by 6 12.9-grade M8 bolts.

[0042] In the present application, the LNG energy storage tank 1 includes multiple pressure relief ports, each of which can be connected to the corrugated energy accumulator 2. Therefore, after any pressure relief port fails, other pressure relief ports can be activated to achieve pressure relief to avoid excessive pressure. Preferably, the LNG energy storage tank 1 includes a first pressure relief port and a second pressure relief port, and one of the first pressure relief port and the second pressure relief port is selectively connected to the corrugated energy accumulator 2; pressure relief can be achieved through both the first pressure relief port and the second pressure relief port. When one of them fails, the other pressure relief port can be activated to relieve pressure, thereby better protecting the safety of the LNG energy storage tank 1.

[0043] Preferably, the opening pressure at the first pressure relief port is less than the opening pressure of the second pressure relief port; the opening pressure of the first pressure relief port is relatively small, so during the pressure relief process, pressure relief is first achieved through the first pressure relief port, and the second pressure relief port is in a closed state. When the first pressure relief port fails, that is, the pressure reaches the opening pressure of the first pressure relief port, but the first pressure relief port does not open. At this time, the pressure will continue to rise until it reaches the opening pressure of the second pressure relief port. At this time, pressure relief is achieved through the second pressure relief port, thereby ensuring that pressure relief can always be achieved through the pressure relief port to protect the safety of the LNG energy storage tank 1.

[0044] In the present application, the opening pressure of the first pressure relief port is 1.76 MPa, and the opening pressure of the second pressure relief port is 2.4 MPa.

[0045] When the first pressure relief port and the second pressure relief port are connected to the bellows accumulator 2, the main safety valve at the first pressure relief port and the auxiliary safety valve at the second pressure relief port are connected to each other through a DN15 pipe, and the material of the pipe is 304 stainless steel; a DN25 metal hose is selected, one end of which is connected to the safety valve at the pressure relief port, and the other end is connected to the bellows accumulator 2, and a ferrule joint is set at the connection to improve the sealing of the connection.

[0046] like Figure 4 and Figure 5 As shown, a corrugated elastic body 23 is provided in the corrugated energy accumulator 2 to separate the corrugated energy accumulator 2 into a bellows energy storage chamber 21 and an energy storage vaporization chamber 22. The corrugated elastic body 23 is located in the bellows energy storage chamber 21. The corrugated elastic body 23 refers to a tubular elastic sensitive element formed by connecting foldable corrugated sheets along the folding and stretching direction. The corrugated elastic body 23 has a thinner wall and a higher sensitivity. When working, it stretches along the length direction of the elastic body under the action of internal pressure. The corrugated elastic body 23 has better elasticity and higher temperature resistance, so that the corrugated energy accumulator 2 can be used under high temperature conditions.

[0047] Preferably, the bellows energy accumulator 2 is further provided with an inflation device, which is unidirectionally connected to the bellows energy storage chamber 21, that is, the inflation device can only inflate the bellows energy storage chamber 21. Since the gas in the bellows energy storage chamber 21 will flow to the energy storage vaporization chamber 22, the gas pressure in the bellows energy storage chamber 21 can be conveniently adjusted by the inflation device, thereby satisfying the pressure balance between the bellows energy storage chamber 21 and the energy storage vaporization chamber 22, so that the energy storage vaporization chamber 22 can work and store gas at a higher pressure; at the same time, the inflation device ensures the pressure balance between the bellows energy storage chamber 21 and the energy storage vaporization chamber 22, ensuring that the corrugated elastomer 23 can change within the elastic range, avoiding the flattening and stretching caused by the internal and external pressure difference.

[0048] like Figure 4 As shown, the corrugated elastic body 23 extends toward the inner wall of the corrugated energy accumulator 2 with several supports 24, and the supports 24 can slide along the inner wall of the corrugated energy accumulator 2; since the gas first enters the bellows energy storage chamber 21 and then enters the energy storage vaporization chamber 22 when entering the corrugated energy accumulator 2 from the LNG energy storage tank 1, the pressure in the bellows energy storage chamber 21 and the energy storage vaporization chamber 22 will be in a constant state of change during the gas flow process, so by providing the corrugated elastic body 23, the movement of the corrugated elastic body 23 can change the pressure in the bellows energy storage chamber 21 and the energy storage vaporization chamber 22. The volume of the bellows energy storage chamber 22 is achieved, thereby satisfying the pressure balance between the bellows energy storage chamber 21 and the energy storage vaporization chamber 22; the support 24 at the corrugated elastic body 23 can play a supporting role, thereby making the corrugated elastic body 23 more stable as a whole, and at the same time, when the support 24 moves, it slides along the inner wall of the corrugated energy accumulator 2, and the friction between the support 24 and the corrugated energy accumulator 2 during sliding is also relatively small, thereby making the movement of the corrugated elastic body 23 more convenient, and the reaction to pressure changes is more sensitive, so as to better ensure that the pressure balance is maintained between the bellows energy storage chamber 21 and the energy storage vaporization chamber 22.

[0049] A one-way valve is provided at the connection point between the bellows energy storage chamber 21 and the energy storage vaporization chamber 22; the one-way valve allows the gas in the bellows energy storage chamber 21 to flow to the energy storage vaporization chamber 22 in only one direction, thereby avoiding irregular pressure changes caused by gas backflow, which makes it difficult to maintain pressure balance between the bellows energy storage chamber 21 and the energy storage vaporization chamber 22.

[0050] Preferably, the pressure in the bellows energy storage chamber is not greater than 0.2MPA, and the pressure in the energy storage vaporization chamber is not greater than the pressure in the bellows energy storage chamber. The unvaporized liquefied gas entering the bellows energy storage chamber will stretch the bellows energy storage device after vaporization. After the internal pressure exceeds 0.2MPa, the one-way valve is opened, and the vaporized gas enters the gas storage chamber through the one-way valve. After the pressure in the energy storage vaporization chamber meets 0.2MPa, the bellows is compressed to the lower position, so that the pressure in the bellows energy storage chamber is balanced with the pressure in the energy storage vaporization chamber. When the system supplies gas, the internal balance pressure is maintained at 0.2MPa. According to the calculation of the vaporization rate, the volume of the bellows energy storage device in this application meets the emission capacity requirement of vehicles parked for at least 6 months, and normal vehicles can meet the zero emission requirements.

[0051] Among them, the liquefied gas inside the LNG energy storage tank is over-pressured and discharged after being vaporized by environmental factors. The function of the corrugated energy storage device is to collect the discharged gas, and the collected gas can be provided to the engine for use. It is understandable that since the pressure relief in the LNG energy storage tank is for the naturally vaporized liquefied gas, not only the vaporized gas will be discharged during the pressure relief, but also some liquid will be taken out. The corrugated energy storage device will collect the incompletely vaporized LNG gas collected in the bellows energy storage chamber and enter the energy storage vaporization chamber through the one-way valve after vaporization. The one-way opening pressure is 0.2MPa and the elastic characteristics of the bellows itself, which can ensure the pressure balance of the two inner and outer chambers. It is understandable that the pressure in the bellows energy storage chamber in this application is set to no more than 0.2MPA in order to meet the pressure value set when the bellows energy storage device is in normal use, and the pressure of the energy storage vaporization chamber is balanced with that of the bellows energy storage chamber. When an abnormality occurs and the pressure in the energy storage vaporization chamber is too large, it is the pressure in the energy storage vaporization chamber under the abnormal state, which does not belong to the state when the application is in normal use. At this time, pressure relief processing is required.

[0052] It can be understood that for the connection between the LNG energy storage tank 1 and the corrugated energy accumulator 2, a one-way valve is set at the first pressure relief port and the second pressure relief port, so that the gas flows from the LNG energy storage tank 1 to the corrugated energy accumulator 2 to avoid gas backflow. Similarly, a one-way valve is also set at the connection between the gas transmission device 26 and the vehicle-mounted vaporizer to also avoid gas backflow.

[0053] The present invention provides a vehicle-mounted natural gas control method without pressure relief emission, which is applied to the above-mentioned vehicle-mounted natural gas system. The control method includes:

[0054] S1: The LNG energy storage tank delivers gas to the bellows energy storage chamber of the bellows energy storage device through the pressure relief port, and gas is generated in the bellows energy storage chamber that can flow to the energy storage vaporization chamber;

[0055] S2: The gas in the bellows energy storage chamber can flow to the energy storage vaporization chamber, so that the pressure of the bellows energy storage chamber and the energy storage vaporization chamber is balanced;

[0056] S3: When the pressure in the energy storage vaporization chamber is greater than 0.45 MPa, the gas in the energy storage vaporization chamber is discharged to the vehicle-mounted vaporizer.

[0057] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A vehicle-mounted natural gas system without pressure relief emission, characterized in that: It includes an LNG energy storage tank and a bellows energy accumulator connected to the LNG energy storage tank, the LNG energy storage tank includes a plurality of pressure relief ports connected to the bellows energy accumulator, the bellows energy accumulator includes a bellows energy storage chamber connected to the pressure relief ports and an energy storage vaporization chamber connected to the bellows energy storage chamber, and the gas in the bellows energy storage chamber can flow to the energy storage vaporization chamber so that the bellows energy storage chamber and the energy storage vaporization chamber maintain pressure balance; The corrugated energy accumulator is provided with a corrugated elastic body to separate the corrugated energy accumulator into the bellows energy storage chamber and the energy storage vaporization chamber, and the corrugated elastic body is located in the bellows energy storage chamber; The corrugated elastic body extends toward the inner wall of the corrugated energy accumulator with a plurality of supports, and the supports are capable of sliding along the inner wall of the corrugated energy accumulator; A one-way valve is provided at the connection between the bellows energy storage chamber and the energy storage vaporization chamber; The bellows energy storage device also includes a vacuum device disposed at the connection between the bellows energy storage chamber and the energy storage vaporization chamber; The energy storage vaporization chamber is provided with a gas delivery device connected to the vehicle-mounted vaporizer, and the vaporized gas in the energy storage vaporization chamber flows to the vehicle-mounted vaporizer through the gas delivery device.

2. A vehicle-mounted natural gas system without pressure relief emissions according to claim 1, characterized in that: The pressure in the bellows energy storage chamber is not greater than 0.2 MPA, and the pressure in the energy storage vaporization chamber is not greater than the pressure in the bellows energy storage chamber.

3. The vehicle-mounted natural gas system without pressure relief emission according to claim 1, characterized in that: The LNG energy storage tank includes a first pressure relief port and a second pressure relief port, and either the first pressure relief port or the second pressure relief port is communicated with the corrugated energy accumulator.

4. A vehicle-mounted natural gas system without pressure relief emissions according to claim 3, characterized in that: The opening pressure at the first pressure relief port is lower than the opening pressure of the second pressure relief port.

5. A vehicle-mounted natural gas control method without pressure relief emission, characterized in that: Applied to the vehicle-mounted natural gas system according to any one of claims 1, 3 and 4, the control method comprises: S1: The LNG energy storage tank delivers gas to the bellows energy storage chamber of the bellows energy storage device through the pressure relief port, and gas that can flow to the energy storage vaporization chamber is generated in the bellows energy storage chamber; S2: The gas in the bellows energy storage chamber can flow to the energy storage vaporization chamber, so that the bellows energy storage chamber and the energy storage vaporization chamber maintain pressure balance; S3: When the pressure in the energy storage vaporization chamber is greater than 0.45 MPa, the gas in the energy storage vaporization chamber is discharged to the vehicle-mounted vaporizer.

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