Vehicle-mounted liquefied natural gas outer tank front end structure

Abstract

This invention discloses a front end cap structure for a vehicle-mounted liquefied natural gas (LNG) outer liner, specifically relating to the field of mechanical technology. It includes a front end cap body comprising a first valve body for liquid inlet and a second valve body for liquid outlet. The first valve body is fixedly connected to the outer end of the front end cap body. The bottom of the first valve body has a first liquid inlet hole, a first vent hole, and a first liquid outlet hole. A second liquid inlet hole, connected to the first liquid inlet hole, is circumferentially formed on the first valve body. The first liquid inlet hole is connected to the inner cavity of the inner liner via a pipeline. A diversion groove is formed in the first liquid outlet hole, and a movable column is installed within the diversion groove. This invention minimizes the amount of liquefied natural gas flowing into the second liquid outlet hole through the gap between the movable column and the placement groove, preventing the problem of the shut-off valve opening too quickly before vehicle start-up when the pressure of the LNG in the inner liner is high, thus preventing the one-way valve in the pipeline from being damaged due to overcooling caused by the low-temperature liquefied natural gas.

Description

Technical Field

[0001] This invention relates to the field of vehicle-mounted liquefied natural gas (LNG) technology, and more specifically, to the front end cap structure of the outer tank of vehicle-mounted LNG. Background Technology

[0002] Liquefied natural gas (LNG) is produced by purifying natural gas from gas fields and then liquefying it under ultra-low temperature (-162℃) pressure. Its main component is methane, which is colorless, odorless, non-toxic, and non-corrosive. Its volume is about 1 / 600th of the same amount of gaseous natural gas, and its weight is only about 45% of the same volume of water. With the intensification of global warming, the use of clean, environmentally friendly, and renewable energy is an inevitable trend in today's development.

[0003] Chinese patent application number 201210495996.9 discloses a front end cap structure for a vehicle-mounted liquefied natural gas (LNG) outer liner. The structure includes a supporting valve seat with a through hole, three supporting side holes perpendicular to and extending through the through hole; a filling valve seat with a central hole, and sequentially arranged vertically through the central hole with a filling hole, a pressure gauge hole, a safety valve hole, a regulator hole, and a vent valve hole; and a liquid outlet connector with a through hole, one end of which is an inner hole and the other an outer hole, with a liquid outlet hole perpendicularly through the through hole. The front end cap, supporting valve seat, filling valve seat, and the inner hole end of the liquid outlet connector are sequentially fixed. The three supporting side holes are respectively fixed to three supporting pins. The filling hole, pressure gauge hole, safety valve hole, regulator hole, and vent valve hole are all sequentially fixed to the filling valve, pressure gauge valve, safety valve, economic regulator valve, and vent valve via pipes. The outer hole end and the liquid outlet hole are both fixed to the sensing pressure gauge and the liquid outlet valve via pipes. This structure is used for support and filling / discharging LNG. The invention ensures stable support and safety during filling, adjustment, and venting of the liquid. However, it does not consider that during use, due to the low temperature of liquefied natural gas, the structure at the outlet may freeze over with frost during long-term use.

[0004] However, in existing technologies, because the front end cap of the outer liner is exposed to the air, the outlet valve needs to be opened before the vehicle starts. If the outlet valve is opened too quickly, the temperature of the liquefied natural gas stored in the container is extremely low, about -162 degrees Celsius. As the liquefied natural gas passes through the pipeline, the one-way valve in the pipeline will be damaged due to overcooling. During vehicle use, low-temperature liquefied natural gas will continuously flow out of the pipeline from the outlet valve and be transported to the carburetor. The outlet valve and the surrounding pipeline are in an ultra-low temperature state as the vehicle is moving, which causes the valve and pipeline to frost. In more serious cases, the outlet valve and pipeline will freeze. The frozen outlet valve will not be able to close in an emergency, affecting driving safety. Therefore, this invention proposes a front end cap structure for the vehicle-mounted liquefied natural gas outer liner to solve the above problems. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide a front end cap structure for the outer liner of a vehicle-mounted liquefied natural gas tank, which solves the problems mentioned in the background art by setting a first valve body 2 and a second valve body 3.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a vehicle-mounted liquefied natural gas outer liner front end cap structure, comprising: an outer liner front end cap body, wherein the outer liner front end cap body includes a first valve body for liquid inlet and a second valve body for liquid outlet;

[0007] The first valve body is fixedly connected to the outer end of the front end cap of the outer liner. The bottom of the first valve body is provided with a first liquid inlet, a first vent, and a first liquid outlet. The first valve body is provided with a second liquid inlet that is connected to the first liquid inlet in the circumferential direction. The first liquid inlet is connected to the inner cavity of the inner liner through a pipeline. The first liquid outlet is provided with a diversion groove and a moving column is provided in the diversion groove.

[0008] The second valve body is fixedly connected to one end of the first valve body. The second valve body has a second vent hole and a second liquid outlet hole respectively opened at the end of the second valve body near the first valve body. A placement groove is opened in the second liquid outlet hole.

[0009] An elastic element is provided between the first valve body and the second valve body, and the two ends of the elastic element are respectively connected to the bottom end of the placement groove and one end of the moving column.

[0010] Preferably, the first vent hole and the first liquid outlet hole both penetrate the first valve body. The second valve body is circumferentially provided with an air inlet hole and an air outlet hole that communicate with the first vent hole. The second valve body is circumferentially provided with a third liquid outlet hole that communicates with the first liquid outlet hole. The third liquid outlet hole is connected to a pressure gauge through an external pipeline. The pressure gauge is used to display the pressure of the natural gas solution in the inner tank. The external pipeline of the third liquid outlet hole is also connected to a safety valve. The safety valve is used for overpressure overflow of the natural gas solution in the inner tank.

[0011] Preferably, the second valve body has an output hole circumferentially away from the second vent hole and the second liquid outlet hole. The second valve body has a first guide groove and a second guide groove. The first guide groove is connected to the second vent hole, and the second guide groove is connected to the second liquid outlet hole. A sliding groove is formed between the first guide groove and the second guide groove in the second valve body. The sliding groove is connected to the first guide groove and the second guide groove. The second valve body has a first connecting groove and a second connecting groove. Both the first connecting groove and the second connecting groove are connected to the output hole and the sliding groove.

[0012] Preferably, a sliding column is slidably connected in the slid groove, and a liquid guiding hole communicating with the second guide groove is opened circumferentially in the second valve body. The liquid guiding hole is coaxial with the sliding column, and a guide column is fixedly connected to one end of the sliding column near the liquid guiding hole. The guide column is coaxial with the liquid guiding hole.

[0013] Preferably, the sliding column is composed of a cylinder and two frustums, with the frustums located on both sides of the cylinder. The guide column is composed of a cylinder and frustums, with the frustums of the guide column cooperating with the liquid guiding hole.

[0014] Preferably, the movable column is composed of a cylinder, a frustum, and a ring. The ring and the cylinder are located at opposite ends of the cylinder. One end of the frustum of the movable column is adapted to the first liquid outlet hole, and one end of the ring on one side of the movable column is used to limit the elastic element.

[0015] Preferably, the diameter of the movable column is smaller than the diameter of the diversion channel.

[0016] Preferably, the outer liner front end cap body has a hole below the first valve body, and a connecting pipe is fixedly connected through the hole. The connecting pipe is connected to the bottom of the inner cavity of the inner liner through a pipeline, and the connecting pipe is connected to the pressurizing device through a pipeline. A shut-off valve is provided in the pipeline between the connecting pipe and the pressurizing device. The second liquid inlet is connected to the external liquid filling pipe through a pipeline. The external liquid filling pipe is equipped with a one-way valve to prevent the backflow of liquefied natural gas.

[0017] Preferably, the output port is connected to a shut-off valve via a pipeline, the shut-off valve is connected to a vaporization device via a pipeline, the vaporization device is connected to the vehicle's engine, the liquid guide port is connected to the delivery pipe of the booster device via a pipeline, the air inlet is connected to the output pipe of the booster device via a pipeline, and the air inlet is connected to the vaporization device via a pipeline.

[0018] Preferably, the vent is connected to a safety valve via a pipe, and the first vent is connected to the top of the inner liner via a pipe.

[0019] The technical effects and advantages of this invention are as follows:

[0020] 1. This invention maximizes the compression distance of the elastic element by using a moving column, and the end face of the moving column is closest to the second valve body. The amount of liquefied natural gas flowing into the second outlet hole through the gap between the moving column and the placement groove is minimized. This prevents the problem of the shut-off valve opening too quickly before the vehicle starts when the pressure of the gasified natural gas and liquefied natural gas in the inner tank is high, thus preventing the one-way valve in the pipeline from being damaged by overcooling due to the low temperature of the liquefied natural gas.

[0021] 2. This invention minimizes the compression distance of the elastic element by using a movable column, and maximizes the distance between the end face of the movable column and the second valve body. This minimizes the amount of liquefied natural gas flowing into the second outlet through the gap between the movable column and the first outlet, thereby preventing the problem of hand injury from excessively cold liquefied natural gas when the pressure of gasified natural gas and liquefied natural gas in the inner tank is low and the shut-off valve is accidentally opened before starting the vehicle without wearing protective gloves.

[0022] 3. This invention reduces the gap between the sliding column, the guide column, and the chute, thus reducing the amount of liquid natural gas flowing through the second connecting chute. Conversely, it increases the gap between the sliding column and the chute, increasing the amount of gasified natural gas flowing through the first connecting chute. The air inlet is connected to the gasification device via a pipeline, allowing the gasified natural gas generated by the pressurization device to re-enter the air inlet. This continuously allows the gasified natural gas to enter the output port through the first connecting chute and is then transported to the gasification device. This cycle repeats, reducing the gasification time of the gasification device and ensuring that more gasified natural gas enters the output port than liquid natural gas. Furthermore, it prevents the problem of frost and freezing of the first valve body, second valve body, and shut-off valve caused by low temperatures of liquid natural gas during vehicle operation.

[0023] 4. This invention minimizes the distance between the sliding column and the liquid guide hole within the sliding groove, prioritizing the use of high-pressure vaporized natural gas in the inner liner. This further ensures that even after the vehicle is turned off, the outer liner will vaporize the liquefied natural gas in the inner liner under high temperatures. When there is a large amount of vaporized natural gas in the inner liner, and the pressure is too high, the vaporized natural gas in the inner liner will be discharged into the atmosphere through the first vent and the outlet via a safety valve. If the surrounding area is not properly protected, this could pose a safety hazard. By reducing the gap between the sliding column, the guide column, and the sliding groove through the vaporized natural gas, the amount of liquefied natural gas flowing through the second connecting groove is reduced, further ensuring that the high-pressure vaporized natural gas in the inner liner is used preferentially. This prevents the phenomenon of the outer liner vaporizing the liquefied natural gas in the inner liner under high temperatures and the high-pressure vaporized natural gas being discharged into the atmosphere through the first vent and the outlet via a safety valve, further ensuring that the vehicle has sufficient energy when starting.

[0024] 5. This invention opens the shut-off valve at the connecting pipe, allowing the liquefied natural gas at the bottom of the inner tank to enter the booster device through the connecting pipe under the action of gasified natural gas. The booster device gasifies the liquefied natural gas, and part of the gasified natural gas enters the gasification device through the air inlet to provide power to the engine, while part of the gasified natural gas enters the first vent through the air inlet. The gasified natural gas in the output hole enters the liquid guide hole through the gap between the sliding column, the guide column, and the slide groove. The gasified natural gas mixes with the liquefied natural gas through the pipeline connected to the connecting pipe via the liquid guide hole, further ensuring that the vehicle can travel a certain distance normally when the gas pressure is low. The mixed gasified natural gas and liquefied natural gas further prevent the problem of frost formation on the pipeline between the connecting pipe and the booster device. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the front end cap of the outer liner of the present invention.

[0026] Figure 2 This is a schematic diagram of the connecting pipe structure of the present invention.

[0027] Figure 3 This is a schematic diagram of the installation of the front end cap of the outer liner of the present invention.

[0028] Figure 4 This is a partial sectional view of the front end cap of the outer liner of the present invention after installation.

[0029] Figure 5 This is a full cross-sectional schematic diagram of the main body of the outer liner front end cap of the present invention located at the third liquid outlet.

[0030] Figure 6 This is a schematic diagram of the connection of the first liquid inlet pipe of the present invention.

[0031] Figure 7 This is a rotated cross-sectional view of the flow divider of the present invention.

[0032] Figure 8 This is an exploded view of the second valve body of the present invention.

[0033] Figure 9 This is an exploded view of the first valve body of the present invention.

[0034] Figure 10 This is a cross-sectional view of the first liquid outlet hole of the present invention.

[0035] Figure 11 This is a cross-sectional view of the first vent hole of the present invention.

[0036] Figure 12 This is a cross-sectional view of the first liquid inlet hole of the present invention.

[0037] Figure 13 This is a cross-sectional view of the second liquid outlet hole of the present invention.

[0038] Figure 14 This is a cross-sectional view of the second vent of the present invention.

[0039] Figure 15 This is a cross-sectional view of the second valve body of the present invention.

[0040] Figure 16 This is a schematic diagram of the full cross-section of the sliding column of the present invention.

[0041] The attached figures are labeled as follows: 1. Outer liner front end cap body; 2. First valve body; 21. First liquid inlet; 22. First vent; 23. First liquid outlet; 231. Diverter groove; 24. Second liquid inlet; 25. Moving column; 26. Air inlet; 27. Air outlet; 28. Third liquid outlet; 3. Second valve body; 31. Second vent; 32. Second liquid outlet; 321. Placement groove; 33. Output hole; 34. First guide groove; 341. First connecting groove; 35. Second guide groove; 351. Second connecting groove; 36. Sliding groove; 37. Sliding column; 38. Liquid guide hole; 39. Guide column; 4. Elastic element; 5. Hole; 51. Connecting pipe. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1

[0044] In actual use, since the front end cap of the outer liner is exposed to the air, the outlet valve needs to be opened before the vehicle is started. Liquid natural gas is stored in the container at low temperature. If the outlet valve is opened too quickly, the liquid natural gas will pass through the pipeline in the front end cap of the outer liner at room temperature, causing the one-way valve in the pipeline to be damaged due to overcooling. This embodiment is invented to solve the above problem.

[0045] Please see Figure 1 As shown, an embodiment of the vehicle-mounted liquefied natural gas (LNG) outer tank front end cap structure of the present invention includes: an outer tank front end cap body 1, the outer tank front end cap body 1 including a first valve body 2 for liquid inlet and a second valve body 3 for liquid outlet; combined with Figure 6 , Figure 9 and Figure 12The first valve body 2 is fixedly connected to the outer end of the front end cap 1 of the outer liner. The bottom of the first valve body 2 is provided with a first inlet hole 21, a first vent hole 22, and a first outlet hole 23. A second inlet hole 24, connected to the first inlet hole 21, is circumferentially provided on the first valve body 2. The first inlet hole 21 is connected to the inner cavity of the inner liner via a pipe. A diversion groove 231 is provided inside the first outlet hole 23, and a moving column 25 is installed within the diversion groove 231. Figure 8 The second valve body 3 is fixedly connected to one end of the first valve body 2. The second valve body 3 is provided with a second vent hole 31 and a second liquid outlet hole 32 at the end near the first valve body 2. A placement groove 321 is provided in the second liquid outlet hole 32. An elastic element 4 is provided between the first valve body 2 and the second valve body 3. The two ends of the elastic element 4 are connected to the bottom end of the placement groove 321 and one end of the moving column 25, respectively. The elastic element 4 is a spring.

[0046] Please see Figure 10 and Figure 11 As shown, the first vent 22 and the first liquid outlet 23 both penetrate the first valve body 2. The second valve body 3 has an inlet 26 and an outlet 27 connected to the first vent 22, and a third liquid outlet 28 connected to the first liquid outlet 23, which are circumferentially connected to the first vent 22. Figure 3 , Figure 4 and Figure 6 The third outlet 28 is connected to a pressure gauge via an external pipeline. The pressure gauge is used to display the pressure of the natural gas solution in the inner tank. The external pipeline of the third outlet 28 is also connected to a safety valve, which is used to allow the natural gas solution in the inner tank to overflow due to overpressure.

[0047] Please see Figure 5 and Figure 7 As shown, the movable column 25 consists of a cylinder, a frustum, and a ring. The ring and the cylinder are located at opposite ends of the cylinder. One end of the frustum of the movable column 25 is fitted with the first liquid outlet 23. Figure 9 As shown, one end of the ring on one side of the movable column 25 is used to limit the elastic element 4, and the diameter of the movable column 25 is smaller than the diameter of the diversion groove 231. Please refer to... Figure 2 , Figure 3 and Figure 5 As shown, a hole 5 is provided on the outer liner front end cap 1 below the first valve body 2. A connecting pipe 51 is fixedly connected through the hole 5. The connecting pipe 51 is connected to the bottom of the inner liner cavity via a pipeline. The connecting pipe 51 is also connected to a pressurizing device via a pipeline. A shut-off valve is installed in the pipeline between the connecting pipe 51 and the pressurizing device. The second liquid inlet 24 is connected to an external liquid filling pipe via a pipeline. The external liquid filling pipe is equipped with a one-way valve to prevent the backflow of liquefied natural gas. Figure 3 and Figure 4As shown, the output port 33 is connected to a shut-off valve via a pipeline, the shut-off valve is connected to a vaporization device via a pipeline, the vaporization device is connected to the vehicle's engine, the liquid guide port 38 is connected to the supercharger's delivery pipe via a pipeline, the air inlet port 26 is connected to the supercharger's output pipe via a pipeline, the air inlet port 26 is connected to the vaporization device via a pipeline, the air outlet port 27 is connected to a safety valve via a pipeline, and the first vent port 22 is connected to the top of the inner liner via a pipeline. It should be noted that the supercharger, vaporization device, shut-off valve, safety valve, and inner and outer liner are all existing technologies and will not be described in detail here.

[0048] During use, liquefied natural gas (LNG) is stored in the inner tank, with the LNG at the bottom and the vaporized natural gas at the top. When the LNG level in the inner tank is low, the vehicle may experience insufficient power while driving. In this case, the vehicle needs to be driven to a gas station for refueling. The refueling equipment is connected to the pipeline connected to the second inlet port 24. The refueling equipment pressurizes the LNG through the second inlet port 24 and introduces it into the first inlet port 21. The LNG then enters the inner tank for storage through the pipeline connected to the first inlet port 21. When there is a large amount of vaporized natural gas in the inner tank, it becomes impossible to deliver more LNG. In this case, the gas needs to be released through the outlet. The safety valve in the external pipeline of hole 27 is opened, allowing the vaporized natural gas in the inner tank to be discharged into the atmosphere through the first vent hole 22 and the vent hole 27 via the safety valve. During the venting and refueling process, a warning line must be set up around the vehicle, and any open flames or actions that may cause safety hazards are prohibited. When the liquefied natural gas is full, some natural gas will enter the buffer tank in the inner tank. The buffer tank in the inner tank has a vertical through hole. After the liquefied natural gas enters the buffer tank through the hole, it will increase the proportion of vaporized natural gas at the top of the inner tank. This prevents low gas pressure when starting the vehicle and ensures that the vehicle can start normally. The liquefied natural gas in the inner tank is powered by vaporized natural gas.

[0049] Before the vehicle is started, if the shut-off valve at the output port 33 is opened quickly, the liquefied natural gas in the inner tank will be squeezed by the vaporized natural gas to the first liquid outlet port 23. The high-pressure liquefied natural gas in the first liquid outlet port 23 squeezes the moving column 25. The moving column 25 moves in the diversion groove 231 and squeezes the elastic element 4. Under the action of the high-pressure liquefied natural gas impacting the moving column 25, the elastic element 4 is compressed. At the same time, the moving column 25 approaches the second valve body 3, and the liquefied natural gas passes through the gap between the moving column 25 and the first liquid outlet port 23.

[0050] When the pressure of the vaporized natural gas in the inner tank is high, the pressure of the liquid natural gas in the inner tank squeezing the moving column 25 through the first liquid outlet 23 is also high. At this time, the moving speed of the moving column 25 in the diversion groove 231 increases. While the moving column 25 moves towards the second valve body 3, it squeezes the elastic element 4. The elastic element 4 is compressed. The distance between the moving column 25 and the second valve body 3 changes with the pressure of the liquid natural gas. When the pressure of the liquid natural gas in the inner tank squeezing the moving column 25 through the first liquid outlet 23 is the maximum, the moving column 25 makes the compression distance of the elastic element 4 the maximum. At this time, the end face of the moving column 25 is closest to the second valve body 3, and the amount of liquid natural gas flowing into the second liquid outlet 32 ​​through the moving column 25 and the placement groove 321 is the minimum.

[0051] In summary, by using the movable column 25 to maximize the compression distance of the elastic element 4, the end face of the movable column 25 is closest to the second valve body 3, and the amount of liquefied natural gas flowing into the second outlet hole 32 through the gap between the movable column 25 and the placement groove 321 is minimized. This prevents the shut-off valve from opening too quickly before the vehicle starts when the pressure of the gasified natural gas and liquefied natural gas in the inner tank is high, thus preventing the one-way valve in the pipeline from being damaged due to overcooling caused by the low temperature of the liquefied natural gas.

[0052] When the pressure of the vaporized natural gas in the inner tank is low, the pressure of the liquid natural gas in the inner tank squeezing the moving column 25 through the first liquid outlet 23 is also low. At this time, the moving speed of the moving column 25 in the diversion groove 231 is slower than when the pressure of the vaporized natural gas in the inner tank is higher. While the moving column 25 moves towards the second valve body 3, it squeezes the elastic element 4. The elastic element 4 is compressed. The distance between the moving column 25 and the second valve body 3 changes with the pressure of the liquid natural gas. When the pressure of the liquid natural gas in the inner tank squeezing the moving column 25 through the first liquid outlet 23 is the minimum, the moving column 25 makes the compression distance of the elastic element 4 the minimum. At this time, the end face of the moving column 25 is the farthest from the second valve body 3, and at the same time, the amount of liquid natural gas flowing into the second liquid outlet 32 ​​through the gap between the moving column 25 and the first liquid outlet 23 is the minimum.

[0053] In summary, by using the movable column 25 to minimize the compression distance of the elastic element 4 and to maximize the distance between the end face of the movable column 25 and the second valve body 3, the amount of liquefied natural gas flowing into the second outlet hole 32 through the gap between the movable column 25 and the first outlet hole 23 is minimized. This prevents the phenomenon of hand injury from excessively cold liquefied natural gas when the pressure of gasified natural gas and liquefied natural gas in the inner tank is low and the shut-off valve is accidentally opened before starting the vehicle without wearing protective gloves.

[0054] Example 2

[0055] In actual use, it was found that simply using the moving column 25 to maximize or minimize the compression distance of the elastic element 4 can only control the flow rate of liquefied natural gas entering the second outlet 32. As the liquefied natural gas flows through the second outlet 32 ​​into the output port 33 and the shut-off valve, with the vehicle being used for a long time, the liquefied natural gas continuously enters the output port 33 and the shut-off valve through the second outlet 32. The low temperature of the liquefied natural gas causes frost and freezing on the first valve body 2, the second valve body 3, and the shut-off valve, making it impossible to close the shut-off valve in time after the vehicle stops, which poses a safety hazard. Therefore, further improvements have been made based on the above embodiment.

[0056] Please see Figure 13 and Figure 14 As shown, the second valve body 3 has an output hole 33 circumferentially away from the second vent hole 31 and the second liquid outlet hole 32. The second valve body 3 has a first guide groove 34 and a second guide groove 35. The first guide groove 34 is connected to the second vent hole 31, and the second guide groove 35 is connected to the second liquid outlet hole 32. The second valve body 3 has a sliding groove 36 between the first guide groove 34 and the second guide groove 35. The sliding groove 36 is connected to the first guide groove 34 and the second guide groove 35. The second valve body 3 has a first connecting groove 341 and a second connecting groove 351. The first connecting groove 341 and the second connecting groove 351 are both connected to the output hole 33 and the sliding groove 36.

[0057] Please see Figure 15 and Figure 16 As shown, a sliding column 37 is slidably connected inside the slide groove 36. The second valve body 3 has a liquid guiding hole 38 that communicates with the second guide groove 35 in the circumferential direction. The liquid guiding hole 38 is coaxial with the sliding column 37. A guide column 39 is fixedly connected to one end of the sliding column 37 near the liquid guiding hole 38. The guide column 39 is coaxial with the liquid guiding hole 38. The sliding column 37 is composed of a cylinder and two frustums, with the frustums on both sides of the cylinder. The guide column 39 is composed of a cylinder and a frustum. The frustum of the guide column 39 cooperates with the liquid guiding hole 38.

[0058] Based on the above embodiment, during use, before starting the vehicle, the shut-off valve at the output port 33 is opened quickly, and the liquefied natural gas in the inner tank is squeezed by the vaporized natural gas to the first liquid outlet port 23. The high-pressure liquefied natural gas in the first liquid outlet port 23 squeezes the moving column 25. While the moving column 25 moves in the diversion groove 231, it squeezes the elastic element 4. Under the action of the high-pressure liquefied natural gas impacting the moving column 25, the elastic element 4 is compressed. At the same time, the moving column 25 approaches the second valve body 3, and the liquefied natural gas enters the placement groove 321 through the gap between the moving column 25 and the second valve body 3, and enters the second liquid outlet port 32 through the placement groove 321. At the same time, the high-pressure vaporized natural gas at the top of the inner tank enters the first vent port 22, and the high-pressure vaporized natural gas in the first vent port 22 enters the second vent port 31 through the second valve body 3.

[0059] When the pressure of the high-pressure vaporized natural gas in the inner tank is high, the vaporized natural gas compresses the liquefied natural gas. Simultaneously, the vaporized natural gas enters the first guide channel 34 through the first vent 22 and the second vent 31. At the same time, the liquefied natural gas, compressed by the vaporized natural gas, compresses the moving column 25 through the first liquid outlet 23. The moving column 25, while compressing the elastic element 4, moves within the diversion channel 231. The liquefied natural gas flows into the second liquid outlet 32 ​​through the gap between the moving column 25 and the placement channel 321, and then enters the second guide channel through the second liquid outlet 32. Within 35, gasified natural gas enters the first connecting channel 341 through the gap between the sliding column 37 and the sliding groove 36, while liquefied natural gas enters the second connecting channel 351 through the gap between the sliding column 37 and the sliding groove 36. The gasified natural gas and liquefied natural gas mix in the output hole 33 through the first connecting channel 341 and the second connecting channel 351 respectively. After the liquefied natural gas and gasified natural gas are mixed, the amount of liquefied natural gas flowing through the output hole 33 is reduced, thereby preventing the problem of frost and ice formation on the shut-off valve at the output hole 33 during long-term vehicle operation.

[0060] Based on the above, the vaporized natural gas in the inner liner enters the first guide channel 34 through the first vent 22 and the second vent 31. The vaporized natural gas then enters the first connecting channel 341 through the gap between the sliding column 37 and the chute 36. The liquefied natural gas, through the first outlet 23, compresses the moving column 25. The moving column 25 moves within the diversion channel 231, and as it moves towards the second valve body 3, it compresses the elastic element 4. The elastic element 4 is compressed, and the liquefied natural gas enters the second outlet 32 ​​through the placement groove 321 through the gap between the moving column 25 and the second valve body 3. The liquefied natural gas then enters the second guide channel 35 through the second outlet 32. Finally, the liquefied natural gas enters the second connecting channel 351 through the gap between the sliding column 37, the guide column 39, and the chute 36. Due to the high pressure of the vaporized natural gas, it passes through the gap between the sliding column 37 and the chute 36... During the gap, the gasified natural gas pushes the sliding column 37 to slide in the guide hole 38 within the chute 36. As the sliding column 37 slides closer to the guide hole 38, the gap between the sliding column 37 and the chute 36 increases, thus increasing the amount of gasified natural gas flowing through the first connecting channel 341. At the same time, the gasified natural gas pushes the sliding column 37 to slide in the guide hole 38 within the chute 36, reducing the gap between the sliding column 37, the guide column 39, and the chute 36, thus reducing the amount of liquid natural gas flowing through the second connecting channel 351. Simultaneously, as the gap between the guide column 39 and the guide hole 38 decreases, the amount of liquid natural gas entering the pressurization device's delivery pipe through the guide hole 38 and the pipeline also decreases. The air inlet 26 is connected to the output pipe of the pressurization device through a pipeline, and the air inlet 26 is also connected to the gasification device through a pipeline, allowing the gasified natural gas generated by the pressurization device to re-enter the air inlet 26.

[0061] In summary, by varying the distance between the sliding column 37 and the liquid guide hole 38 within the sliding groove 36, when the pressure of the vaporized natural gas in the inner liner is high, the vaporized natural gas causes the sliding column 37 to slide within the sliding groove 36 towards the liquid guide hole 38. This reduces the gap between the sliding column 37, the guide column 39, and the sliding groove 36, thus decreasing the amount of liquid natural gas flowing through the second connecting groove 351. Simultaneously, the gap between the sliding column 37 and the sliding groove 36 increases, leading to an increase in the amount of vaporized natural gas flowing through the first connecting groove 341. The air inlet 26 is connected to the output pipe of the booster device via a pipeline. The air inlet 26 is connected to the gasification device through a pipeline, allowing the gasified natural gas generated by the booster device to re-enter the air inlet 26. The gasified natural gas is continuously fed into the outlet 33 through the first connecting groove 341 and then transported to the gasification device through the outlet 33. This cycle is repeated to reduce the gasification time of the gasification device and ensure that more gasified natural gas than liquid natural gas enters the outlet 33. This further prevents the problem of frost and freezing of the first valve body 2, the second valve body 3, and the shut-off valve caused by the low temperature of liquid natural gas during vehicle operation.

[0062] By minimizing the distance between the sliding column 37 and the liquid guide hole 38 within the sliding groove 36, the high-pressure vaporized natural gas in the inner liner is preferentially used. This further ensures that after the vehicle is turned off, the liquid natural gas in the inner liner will vaporize under high temperatures in the outer liner. When there is a large amount of vaporized natural gas in the inner liner and the pressure is too high, the vaporized natural gas in the inner liner will be discharged into the atmosphere through the first vent hole 22 and the vent hole 27 via the safety valve. If the surrounding precautions are not adequate, there will be a safety hazard. By reducing the gap between the sliding column 37, the guide column 39 and the sliding groove 36 through the vaporized natural gas, the amount of liquid natural gas flowing through the second connecting groove 351 is reduced, further ensuring that the high-pressure vaporized natural gas in the inner liner is preferentially used. This avoids the phenomenon that the liquid natural gas in the inner liner will vaporize under high temperatures in the outer liner and be discharged into the atmosphere through the first vent hole 22 and the vent hole 27 via the safety valve, further ensuring the energy demand when the vehicle starts.

[0063] When the pressure of the vaporized natural gas in the inner tank is low, the vaporized natural gas enters the first guide channel 34 through the first vent 22 and the second vent 31. The vaporized natural gas then enters the first connecting channel 341 through the gap between the sliding column 37 and the sliding groove 36. Meanwhile, the liquid natural gas squeezes the moving column 25 through the first liquid outlet 23. The moving column 25 moves within the diversion channel 231, and as it moves towards the second valve body 3, it squeezes the elastic element 4. The elastic element 4 is compressed, and the liquid natural gas enters the second liquid outlet 32 ​​through the placement groove 321 through the gap between the moving column 25 and the second valve body 3. The liquid natural gas then enters the second guide channel 35 through the second liquid outlet 32. Finally, the liquid natural gas passes through the sliding column 37 and the guide column 36. The gap between the sliding column 37 and the chute 36 leads to the second connecting channel 351. Due to the low pressure of the gasified natural gas, when the gasified natural gas passes through the gap between the sliding column 37 and the chute 36, the sliding distance of the sliding column 37 to the guide hole 38 in the chute 36 is reduced, thereby increasing the gap between the sliding column 37, the guide column 39 and the chute 36. As a result, more liquid natural gas flows through the second connecting channel 351. At the same time, the gap between the guide column 39 and the guide hole 38 increases, and more liquid natural gas enters the delivery pipe of the pressurizing device through the guide hole 38 and the pipeline. The pressurizing device gasifies the liquefied natural gas, and the gasified natural gas enters the air inlet 26. The air inlet 26 is connected to the gasification device through the pipeline.

[0064] When the amount of liquefied natural gas in the inner tank is low, a low gas pressure alarm is triggered. The vaporized natural gas cannot further pass through the first outlet 23, forcing the moving column 25 into the second outlet 32. Conversely, the liquefied natural gas cannot further pass through the second outlet 32 ​​into the second guide channel 35. At this point, the shut-off valve at the connecting pipe 51 needs to be opened. Under the influence of the vaporized natural gas, the liquefied natural gas at the bottom of the inner tank is connected to the bottom of the inner tank cavity via the connecting pipe 51. The connecting pipe 51 is connected to the pressurizing device via a pipeline, and a shut-off valve is installed in the pipeline between the connecting pipe 51 and the pressurizing device. By opening the shut-off valve, the liquefied natural gas enters the pressurizing device through the connecting pipe 51. The pressurizing device vaporizes the liquefied natural gas, and a portion of the vaporized natural gas passes through the intake gas... The gasified natural gas enters the gasification device through the inlet 26 to provide power to the engine. A portion of the gasified natural gas enters the first vent 22 through the inlet 26 and then enters the top of the inner liner through the first vent 22 and the pipe to continue to compress the liquid natural gas in the inner liner. A portion of the gasified natural gas enters the first guide channel 34 through the first vent 22 and the second vent 31. The gasified natural gas enters the first connecting channel 341 through the gap between the sliding column 37 and the slide groove 36. The gasified natural gas enters the outlet 33 through the first connecting channel 341. The gasified natural gas in the outlet 33 enters the liquid guide hole 38 through the gap between the sliding column 37, the guide column 39 and the slide groove 36. The gasified natural gas mixes with the liquid natural gas through the pipeline connected to the connecting pipe 51 via the liquid guide hole 38.

[0065] In summary, by opening the shut-off valve at the connecting pipe 51, the liquefied natural gas at the bottom of the inner tank, under the action of gasified natural gas, enters the booster device through the connecting pipe 51. The booster device gasifies the liquefied natural gas, and part of the gasified natural gas enters the gasification device through the air inlet 26 to provide power to the engine, while part of the gasified natural gas enters the first vent 22 through the air inlet 26. The gasified natural gas in the outlet 33 enters the liquid guide hole 38 through the gap between the sliding column 37, the guide column 39 and the slide groove 36. The gasified natural gas mixes with the liquefied natural gas through the pipeline connected to the connecting pipe 51 via the liquid guide hole 38, further ensuring that the vehicle can travel a certain distance normally when the gas pressure is low. The mixed gasified natural gas and liquefied natural gas further prevent the problem of frost formation on the pipeline between the connecting pipe 51 and the booster device.

[0066] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A front head structure of a vehicle-mounted liquefied natural gas outer can, characterized by, include: The outer liner front end cap body includes a first valve body for liquid inlet and a second valve body for liquid outlet; The first valve body is fixedly connected to the outer end of the front end cap of the outer liner. The bottom of the first valve body is provided with a first liquid inlet, a first vent, and a first liquid outlet. The first valve body is provided with a second liquid inlet that is connected to the first liquid inlet in the circumferential direction. The first liquid inlet is connected to the inner cavity of the inner liner through a pipeline. The first liquid outlet is provided with a diversion groove and a moving column is provided in the diversion groove. The second valve body is fixedly connected to one end of the first valve body. The second valve body has a second vent hole and a second liquid outlet hole respectively opened at the end of the second valve body near the first valve body. A placement groove is opened in the second liquid outlet hole. An elastic element is provided between the first valve body and the second valve body, and the two ends of the elastic element are respectively connected to the bottom end of the placement groove and one end of the moving column. The first vent hole and the first liquid outlet hole both penetrate the first valve body. The second valve body has an air inlet hole and an air outlet hole that are connected to the first vent hole in the circumferential direction. The second valve body also has a third liquid outlet hole that is connected to the first liquid outlet hole in the circumferential direction. The third liquid outlet hole is connected to a pressure gauge through an external pipeline. The pressure gauge is used to display the pressure of the natural gas solution in the inner tank. The external pipeline of the third liquid outlet hole is also connected to a safety valve. The safety valve is used to allow the natural gas solution in the inner tank to overflow due to overpressure. The second valve body has an output hole circumferentially away from the second vent hole and the second liquid outlet hole. The second valve body has a first guide groove and a second guide groove. The first guide groove is connected to the second vent hole and the second guide groove is connected to the second liquid outlet hole. A sliding groove is formed between the first guide groove and the second guide groove in the second valve body. The sliding groove is connected to the first guide groove and the second guide groove. The second valve body has a first connecting groove and a second connecting groove. Both the first connecting groove and the second connecting groove are connected to the output hole and the sliding groove. A sliding column is slidably connected inside the slid groove. A liquid guiding hole communicating with the second guide groove is opened circumferentially in the second valve body. The liquid guiding hole is coaxial with the sliding column. A guide column is fixedly connected to one end of the sliding column near the liquid guiding hole. The guide column is coaxial with the liquid guiding hole.

2. The on-board LNG liner front head structure of claim 1, wherein: The sliding column is composed of a cylinder and two frustums, with the frustums located on both sides of the cylinder. The guide column is also composed of a cylinder and frustums, with the frustums of the guide column engaging with the liquid guide hole.

3. The on-board LNG liner front head structure of claim 2, wherein: The movable column is composed of a cylinder, a frustum, and a ring. The ring and the frustum are located at the two ends of the cylinder, respectively. One end of the frustum of the movable column is adapted to the first liquid outlet hole, and one end of the ring on one side of the movable column is used to limit the elastic element.

4. The on-board LNG liner front head structure of claim 3, wherein: The diameter of the moving column is smaller than the diameter of the diversion channel.

5. The on-board LNG liner front head structure of claim 4, wherein: The outer liner front end cap has a hole below the first valve body. A connecting pipe is fixedly connected through the hole. The connecting pipe is connected to the bottom of the inner liner cavity through a pipeline. The connecting pipe is also connected to a pressurizing device through a pipeline. A shut-off valve is installed in the pipeline between the connecting pipe and the pressurizing device. The second liquid inlet is connected to an external liquid filling pipe through a pipeline. All external liquid filling pipes are equipped with one-way valves to prevent liquefied natural gas backflow.

6. The on-board LNG liner front head structure of claim 5, wherein: The output port is connected to a shut-off valve via a pipeline, the shut-off valve is connected to a vaporization device via a pipeline, the vaporization device is connected to the vehicle's engine, the liquid guide port is connected to the delivery pipe of the booster device via a pipeline, the air inlet is connected to the output pipe of the booster device via a pipeline, and the air inlet is connected to the vaporization device via a pipeline.

7. The on-board LNG liner front head structure of claim 6, wherein: The vent is connected to a safety valve via a pipe, and the first vent is connected to the top of the inner liner via a pipe.

Images