Discharged methane recovery device for LNG (Liquefied Natural Gas) heavy truck

Abstract

The utility model relates to the technical field of new energy, in particular to a discharged methane recovery device for an LNG (Liquefied Natural Gas) heavy truck, which comprises a stop valve, an adsorption type storage tank, a methane adsorbent, a safety valve and an electromagnetic valve. According to the device, a methane adsorbent with a high specific surface area is filled in an adsorption type storage tank, methane discharged under overpressure due to heat absorption gasification of liquefied natural gas in a fuel tank of the heavy truck is adsorbed and stored by utilizing a huge inner surface area and a rich micropore structure of the methane adsorbent, and the methane is released to an engine system to combust and output power when an engine of the heavy truck runs. The safety valve ensures that the gas pressure in the adsorption type storage tank and the heavy truck fuel tank is in a safe state under extremely severe working conditions. The discharged methane recovery device has the advantages of being high in recovery efficiency, high in applicability, wide in application range and the like, can effectively reduce the discharge amount of methane of the heavy truck, not only reduces environmental pollution, but also saves energy, and has great promotion significance for energy conservation and emission reduction.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy, and in particular to an emission methane recovery device for LNG heavy trucks. Background Art

[0002] As the global demand for clean energy continues to grow, liquefied natural gas (LNG) is increasingly used as a clean fuel in heavy-duty transport vehicles. However, the storage and transportation safety issues of LNG fuel have also become prominent, especially the methane gas emitted by the LNG in the LNG fuel tank due to heat absorption and gasification, which directly affects the safety of vehicles and the surrounding environment and causes environmental pollution. As the world's second largest greenhouse gas, methane has a huge global warming potential. Methane emissions are closely related to global climate change, have far-reaching and complex impacts on the environment, and pose a threat to human health and ecosystems.

[0003] In order to solve the safety and environmental pollution problems of methane emissions from overpressure in LNG heavy-duty truck fuel tanks, a methane emission recovery device for LNG heavy-duty trucks is proposed. In order to recover the emitted methane in real time, adsorption technology is used to achieve the adsorption of emitted methane. Adsorption technology adopts the principle of physical adsorption, that is, methane molecules are attached to the inner surface of the adsorbent micropores through van der Waals forces, thereby increasing the storage density of methane. A methane-specific adsorbent with a high specific surface area is loaded into the storage tank, and its huge internal surface area and rich microporous structure are used to adsorb and store methane gas molecules at room temperature and medium pressure. The recovered methane can be used as fuel for heavy-duty trucks. The device has the advantages of high recovery efficiency, strong applicability and wide application range. It not only reduces environmental pollution, but also saves energy, and has huge economic and social benefits for reducing methane emissions. Utility Model Content

[0004] Based on the above purpose, the utility model provides an exhaust methane recovery device for LNG heavy trucks, in which a methane adsorbent with a high specific surface area is loaded into an adsorption storage tank, and the methane discharged at overpressure due to the endothermic gasification of the liquefied natural gas in the fuel tank of the heavy truck is adsorbed and stored by using its huge internal surface area and rich microporous structure. When the heavy truck engine is running, since the methane gas pressure inside the adsorption storage tank is greater than the pressure of the natural gas required by the engine, the methane adsorbent inside the adsorption storage tank releases methane into the engine system under the action of depressurization to burn the output power, which can effectively reduce the methane emission.

[0005] The adsorption capacity of methane adsorbent under a specific pressure is about 2-3 times greater than its volume under the same pressure. At the same time, the volume of the adsorption tank and adsorbent can meet the methane emissions under extremely harsh working conditions. It can ensure that the methane emitted at overpressure due to endothermic gasification of liquefied natural gas in the heavy-duty truck fuel tank can be completely adsorbed by the methane adsorbent, which can effectively maintain the safe pressure of the heavy-duty truck fuel tank.

[0006] A methane recovery device for LNG heavy trucks comprises a cut-off valve, an adsorption storage tank, a methane adsorbent, a safety valve and a solenoid valve.

[0007] Furthermore, the cut-off valve adopts a manual cut-off valve structure.

[0008] Furthermore, the adsorption storage tank absorbs the methane gas discharged at overpressure by means of the methane adsorbent filled inside, and then releases the methane gas as fuel for the natural gas engine of the heavy truck by means of decompression.

[0009] Furthermore, the methane adsorbent is a nano-scale activated carbon adsorption material, which has the characteristics of large specific surface area, low-pressure adsorption, low-pressure storage, and stable pressure desorption, and can be recycled.

[0010] Furthermore, the safety valve automatically opens when the methane gas pressure inside the adsorption storage tank exceeds a safety threshold, releasing excess methane gas, thereby maintaining the pressure within a safe range.

[0011] Furthermore, the solenoid valve is driven by 12V or 24V DC and is in a normally closed state.

[0012] Furthermore, in a feasible implementation mode of the utility model, the shut-off valve is installed at the air inlet of the adsorption storage tank, one end of the solenoid valve is installed at the exhaust port of the adsorption storage tank, and the other end of the solenoid valve is connected to the natural gas inlet of the engine through a pipeline. The shut-off valve is in an open state and the solenoid valve is in a closed state.

[0013] When the natural gas engine of a heavy truck is not working, when the LNG in the fuel tank of the heavy truck absorbs heat and gasifies to reach the safe release pressure, the pressure regulating valve opens, the solenoid valve closes, and the discharged methane gas enters the adsorption storage tank. The methane adsorbent in the adsorption storage tank adsorbs and stores methane molecules. When the pressure inside the fuel tank of the heavy truck is lower than the safe release pressure, the pressure regulating valve closes.

[0014] When the natural gas engine of a heavy truck is in operation, the solenoid valve is always in the open state. When the LNG in the fuel tank of the heavy truck absorbs heat and gasifies to reach a safe release pressure, the pressure regulating valve opens, and the discharged methane gas enters the adsorption tank. The methane adsorbent in the adsorption tank adsorbs and stores methane molecules. At the same time, the methane gas in the adsorption tank desorbs from the surface of the methane adsorbent under reduced pressure and enters the engine for combustion, outputting power to the outside.

[0015] When the natural gas engine of a heavy truck is in operation, the solenoid valve is always open. When the pressure inside the fuel tank of a heavy truck is lower than the safe release pressure, the pressure regulating valve is closed. The methane gas in the adsorption tank is desorbed from the surface of the methane adsorbent under reduced pressure and enters the engine for combustion, outputting power externally.

[0016] When the methane gas pressure inside the adsorption storage tank exceeds the safety threshold, the safety valve automatically opens to release excess methane gas, thereby keeping the pressure within a safe range.

[0017] Beneficial effects of the utility model:

[0018] The utility model is to load a methane adsorbent with a high specific surface area into an adsorption storage tank, and utilize its huge internal surface area and rich microporous structure to adsorb and store the methane discharged at overpressure due to the heat absorption and gasification of liquefied natural gas in the fuel tank of a heavy truck, and release the methane to the engine system to burn and output power when the heavy truck engine is running. The methane recovery device has the advantages of high recovery efficiency, strong applicability and wide application range, and can effectively reduce the methane emission of heavy trucks. It not only reduces environmental pollution, but also saves energy, and has great significance for energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of an exhaust methane recovery device for LNG heavy trucks. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0022] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0023] like Figure 1 As shown, a methane emission recovery device for LNG heavy trucks includes an LNG fuel tank 01, a pressure regulating valve 02, a shut-off valve 03, an adsorption storage tank 04, a methane adsorbent 05, a safety valve 06 and a solenoid valve 07.

[0024] The LNG fuel tank 01 is a cryogenic insulated pressure vessel for storing liquefied natural gas. The evaporation rate of LNG is generally lower than 0.2% / day. Considering the extreme working conditions, the vaporized natural gas is calculated at 0.3% / day.

[0025] The pressure regulating valve 02 automatically opens when the methane gas pressure inside the fuel tank exceeds the safety threshold (1.6MPa) to release excess methane gas, thereby keeping the pressure within a safe range.

[0026] The cut-off valve 03 adopts a manual cut-off valve structure with a filter installed inside to intercept solid impurities in the gas.

[0027] The adsorption storage tank 04 absorbs the methane gas discharged at overpressure through the methane adsorbent 05 filled inside, and then releases the methane gas as fuel for the natural gas engine of the heavy truck by reducing the pressure.

[0028] Methane adsorbent 05 is a nano-scale activated carbon adsorption material with the characteristics of large specific surface area, low-pressure adsorption, low-pressure storage, and stable pressure desorption, and can be recycled.

[0029] Safety valve 06 automatically opens when the methane gas pressure inside the adsorption storage tank exceeds the safety threshold of 1.5MPa under extreme working conditions, releasing excess methane gas to keep the pressure within a safe range.

[0030] Solenoid valve 07 is driven by 24V DC and is in a normally closed state. A filter is installed inside to intercept solid impurities in the gas.

[0031] In a feasible implementation scheme of the utility model, a pressure regulating valve 02 is installed on the LNG fuel tank 01, one end of the shut-off valve 03 is connected to the pressure regulating valve 02 through a pipeline, the other end of the shut-off valve 03 is installed at the air inlet of the adsorption storage tank 04, the interior of the adsorption storage tank 04 is filled with methane adsorbent 05, the safety valve 06 is installed on the upper part of the adsorption storage tank 04, one end of the solenoid valve 07 is installed at the exhaust port of the adsorption storage tank, the other end of the solenoid valve is connected to the natural gas inlet of the engine through a pipeline, the shut-off valve 03 is in an open state, and the solenoid valve 07 is in a closed state.

[0032] When the natural gas engine of the heavy truck is not working, when the LNG in the heavy truck LNG fuel tank 01 absorbs heat and gasifies to a safe release pressure of 1.6MPa, the pressure regulating valve 02 opens, and the discharged methane gas enters the adsorption storage tank 03, and the methane adsorbent 04 in the adsorption storage tank 03 adsorbs and stores methane molecules. When the pressure inside the heavy truck LNG fuel tank 01 is lower than the safe release pressure of 1.6MPa, the pressure regulating valve 02 closes.

[0033] When the heavy truck natural gas engine is in operation, the solenoid valve 07 is powered on to open. When the LNG in the heavy truck LNG fuel tank 01 absorbs heat and gasifies to a safe release pressure of 1.6MPa, the pressure regulating valve 02 is opened, and the discharged methane gas enters the adsorption tank 04. The methane adsorbent 05 in the adsorption tank 04 adsorbs and stores methane molecules. At the same time, the methane gas in the adsorption tank 04 desorbs from the surface of the methane adsorbent 05 under reduced pressure and enters the engine for combustion, outputting power to the outside.

[0034] When the heavy truck natural gas engine is in operation, the solenoid valve 07 is powered on to open, and when the pressure inside the heavy truck LNG fuel tank 01 is lower than the safe release pressure of 1.6MPa, the pressure regulating valve 02 is closed. The methane gas in the adsorption tank 04 is desorbed from the surface of the methane adsorbent 05 under reduced pressure and enters the engine for combustion, outputting power externally.

[0035] When the methane gas pressure inside the adsorption storage tank 04 exceeds the safety threshold of 1.5 MPa, the safety valve 06 automatically opens to release excess methane gas directly to the environment, thereby ensuring that the gas pressure inside the LNG fuel tank 01 and the adsorption storage tank 04 are both in a safe state.

[0036] When the adsorption storage tank 04 needs to be inspected and repaired, the shut-off valve 03 is closed manually and the solenoid valve 07 is closed by power off.

[0037] The utility model is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the scope of protection of the utility model.

Claims

1. An exhaust methane recovery device for LNG heavy trucks, characterized in that: An LNG fuel tank (01), a pressure regulating valve (02), a shut-off valve (03), an adsorption storage tank (04), a methane adsorbent (05), a safety valve (06) and a solenoid valve (07), wherein the pressure regulating valve (02) is mounted on the LNG fuel tank (01), one end of the shut-off valve (03) is connected to the pressure regulating valve (02) through a pipeline, the other end of the shut-off valve (03) is mounted on the air inlet of the adsorption storage tank (04), the methane adsorbent (05) is filled in the interior of the adsorption storage tank (04), the safety valve (06) is mounted on the upper part of the adsorption storage tank (04), one end of the solenoid valve (07) is mounted on the exhaust port of the adsorption storage tank, and the other end of the solenoid valve (07) is connected to the natural gas inlet of the engine through a pipeline.

2. The exhaust methane recovery device for LNG heavy trucks according to claim 1 is characterized in that: The cut-off valve (03) adopts a manual cut-off valve structure and is in a normally open state.

3. The exhaust methane recovery device for LNG heavy trucks according to claim 1 is characterized in that: The adsorption storage tank (04) absorbs and discharges methane gas through the methane adsorbent (05) filled inside, and releases methane into the engine system to burn and output power when the natural gas engine of the heavy truck is running.

4. The exhaust methane recovery device for LNG heavy trucks according to claim 3 is characterized in that: The methane adsorbent (05) is a nano-scale activated carbon adsorption material, which has the characteristics of large specific surface area, low-pressure adsorption, low-pressure storage, and stable pressure desorption, and can be recycled.

5. The exhaust methane recovery device for LNG heavy trucks according to claim 1 is characterized in that: The safety valve (06) automatically opens when the methane gas pressure inside the adsorption storage tank exceeds the safety threshold of 1.5 MPa under extreme working conditions, releasing excess methane gas, thereby maintaining the pressure within a safe range.

6. The exhaust methane recovery device for LNG heavy trucks according to claim 1, characterized in that: The solenoid valve (07) is driven by 12V or 24V direct current, is in a normally closed state, and is equipped with a filter inside to intercept solid impurities in the gas.

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