Gas cylinder saturation device for LNG (Liquefied Natural Gas) vehicle
By using air to heat LNG liquid and increasing the pressure in the gas cylinder, the problem that LNG automotive gas cylinders cannot maintain a saturation pressure of 0.8MPa is solved, and the effect of independent saturation and stable gas supply of the gas cylinder is achieved.
Patent Information
- Application Number
- CN202421322569.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-12
- Publication Date
- 2025-04-15
- Estimated Expiration
- 2034-06-12
AI Technical Summary
Existing LNG automotive gas cylinders may not be able to maintain a saturation pressure of 0.8MPa during driving, resulting in unstable power and anchorage.
Inexpensive air is used to increase the LNG liquid temperature through built-in or external heat exchangers, thereby achieving the pressure boost in the cylinder and achieving the purpose of independent saturation.
By increasing the LNG liquid temperature, the pressure in the cylinder can quickly reach and maintain a saturation pressure of 0.8MPa, ensuring the normal operation of the natural gas engine and avoiding the cylinder pressure being reduced due to vehicle bumps.
Smart Images
Figure CN222760708U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of LNG, in particular to a saturation device for an LNG vehicle gas cylinder. Background Art
[0002] The concept of LNG saturation refers to the fact that the standard boiling point of LNG is -162°C. When stored at -162°C, its saturated vapor pressure gauge pressure is "0." In reality, LNG storage temperatures are slightly higher than its standard boiling point, but its saturated vapor pressure gauge pressure is only 0.2MPa-0.3MPa, significantly lower than the required supply pressure for natural gas engines (which is generally above 0.8MPa). Therefore, to meet the gas supply requirements of natural gas engines, the pressure in LNC vehicle gas cylinders must be saturated to a gauge pressure of 0.8MPa.
[0003] LNG vehicle gas cylinders utilize the saturation concept of LNG cryogenic liquid. When in use, highly saturated, low-temperature LNG is added to a certain pressure and added to the inside of the cylinder. Through the saturation principle of gas and liquid, the cylinder can autonomously supply gas to the outside. Through a series of adjustment methods, the gas supply pressure required by the natural gas engine is achieved, and a steady supply of gas is maintained to enable the natural gas engine to operate normally.
[0004] To meet the 0.8MPa gas supply pressure requirement for natural gas engines, LNG filling stations abroad and in most parts of southern my country first use a device to saturate the low-temperature LNG liquid. This increases the LNG liquid temperature and its saturated vapor pressure gauge from 0.2MPa-0.3MPa to over 0.8MPa. The saturated LNG is then filled into LNG vehicle cylinders, which just meets the vehicle's gas supply pressure requirement and enables the normal operation of LNG vehicles. However, this method requires the LNG filling station to saturate the tanks with LNG beforehand. Some filling stations may not saturate the tanks in advance for economic reasons, which can lead to unstable power and even breakdown of the vehicle during driving.
[0005] Some stations in my country (primarily concentrated in northern China) lack LNG saturation equipment and instead directly fill LNG vehicle cylinders with LNG at a saturated vapor pressure of 0.2MPa-0.3MPa. This results in the LNG pressure inside the cylinders failing to meet the required supply pressure for LNG engines. To increase the LNG supply pressure, some cylinder manufacturers, at the request of automakers, add a heat exchanger to the cylinders. This vaporizes and pressurizes the LNG liquid, which is compressed from the 0.2MPa-0.3MPa pressure inside the cylinder, and then returns it to the upper gas phase of the cylinder, where it is then re-pressurized, raising the cylinder pressure to the required supply pressure for the vehicle engine. However, this method relies on the LNG liquid, which is compressed from the 0.2MPa-0.3MPa pressure inside the cylinder, to be re-pressurized and then fed back to the gas phase of the LNG vehicle cylinder to 0.8MPa, meeting the required supply pressure for the LNG engine. This is not a true saturation technology; it is merely a stopgap measure to ensure that LNG vehicle cylinders meet the required supply pressure for natural gas engines. When the vehicle is driving, the gas phase temperature in the gas cylinder is higher than the liquid phase temperature. Therefore, when the gas cylinder is shaken and bumped by the vehicle, the steam on the upper layer of the inner tank will be re-liquefied, causing the pressure of the gas cylinder to decrease. However, bumps are inevitable during the driving of the vehicle, so it is impossible to ensure that the gas cylinder always maintains a saturated pressure of 0.8MPa. Utility Model Content
[0006] The technical problem to be solved by the utility model is to provide a LNG vehicle cylinder saturation device with a simple structure and low manufacturing cost. The device uses air to increase the temperature of the LNG liquid, thereby achieving the purpose of pressurization and self-saturation of the cylinder, ensuring that the cylinder maintains a continuous gas supply and enables the natural gas engine to operate normally.
[0007] If the LNG vehicle cylinder is not fully filled with LNG, some LNG molecules will enter the upper chamber, a process known as "evaporation." As the number of vapor molecules in the upper chamber increases, the generated vapor pressure also increases. At a certain point, the number of vapor molecules in the upper chamber stops increasing. At this point, the number of molecules leaving the liquid and the number of molecules returning from the upper chamber reach a dynamic equilibrium, also known as "saturation." At this point, the pressure generated by the vapor is called the "saturation pressure." For the same substance, the saturation pressure is temperature-dependent. The higher the temperature, the greater the energy possessed by the molecules, the easier it is for them to escape from the liquid and vaporize, and the corresponding saturation pressure increases. A certain temperature corresponds to a certain saturation pressure; the two are not independent. Therefore, when the temperature of the LNG liquid is increased, the pressure of the LNG liquid will also increase, since a certain temperature corresponds to a certain saturation pressure. To ensure the proper operation of the natural gas engine, the technical solution adopted by this utility model utilizes inexpensive air to provide heat to the LNG liquid in the cylinder, raising the temperature of the LNG liquid and thereby increasing the pressure within the cylinder. After experiments, it was found that when the temperature of the LNG liquid in the gas cylinder is raised to above -135°C, it can basically meet the requirement of 0.8 MPa gas supply pressure of the natural gas engine. When the above method of raising the temperature of the LNG liquid in the gas cylinder is adopted, the liquid phase temperature and the gas phase temperature in the gas cylinder are relatively low. Therefore, no matter whether the gas cylinder is shaken or not, the steam in the upper layer of the inner tank will not be secondary liquefied to cause the pressure of the gas cylinder to decrease. The pressure in the gas cylinder will always be maintained above this saturation pressure. In addition, for the convenience of description, "LNG vehicle gas cylinder" can be referred to as "gas cylinder" for short. Based on this concept, the utility model provides the following three technical solutions:
[0008] The first technical solution is to install a built-in heat exchanger in the LNG vehicle gas cylinder. The external high-speed pump continuously draws external air, and the built-in heat exchanger is immersed in the LNG liquid, so that the temperature of the LNG liquid in the inner tank of the LNG vehicle gas cylinder is rapidly increased, thereby achieving the purpose of increasing the pressure of the LNG liquid in the bottle to the saturation pressure.
[0009] The specific plan is: the LNG vehicle gas cylinder saturation device is provided with a built-in heat exchanger at the bottom of the inner liner of the horizontal LNG vehicle gas cylinder, and the built-in heat exchanger is immersed in the LNG liquid in the LNG vehicle gas cylinder when the gas cylinder is in use; a high-speed pump is provided outside the LNG vehicle gas cylinder, and the high-speed pump is connected to the built-in heat exchanger through a pipeline system; the pipeline system includes: an air inlet pipe and an air outlet pipe; one end of the air inlet pipe is connected to the outlet of the high-speed pump, and the other end of the air inlet pipe is connected to the inlet of the built-in heat exchanger, and the inlet of the high-speed pump is connected to the outside air; one end of the air outlet pipe is connected to the outlet of the built-in heat exchanger, and the other end of the air outlet pipe extends out of the LNG vehicle gas cylinder.
[0010] The outlet pipe extending from the LNG vehicle gas cylinder is open at its end and connected to the outside air. In actual use, a valve can be installed on the outlet pipe extending from the LNG vehicle gas cylinder. Furthermore, cold energy can be recovered by connecting the outlet of the outlet pipe extending from the LNG vehicle gas cylinder to the inlet of a cold energy pipe of a device requiring cold energy.
[0011] The second technical solution is to install an external heat exchanger outside the LNG vehicle gas cylinder, and continuously extract the LNG liquid in the LNG vehicle gas cylinder through an external high-speed pump. After heat exchange with cheap external air through the external heat exchanger, the LNG liquid is returned to the LNG liquid in the LNG vehicle gas cylinder, so that the temperature of the LNG liquid in the inner liner of the LNG vehicle gas cylinder is rapidly increased, thereby achieving the purpose of increasing the pressure of the LNG liquid in the bottle to the saturation pressure.
[0012] The specific solution is as follows: the LNG vehicle gas cylinder is placed horizontally, an external heat exchanger and a high-speed pump are arranged outside the LNG vehicle gas cylinder, and the high-speed pump is connected to the external heat exchanger through a pipeline system; the pipeline system includes: a liquid outlet pipe, a first return air pipe and a second return air pipe; one end of the liquid outlet pipe is connected to the inlet of the external heat exchanger, and the other end of the liquid outlet pipe extends into the bottom of the inner tank of the LNG vehicle gas cylinder, and when the gas cylinder is in use, the end of the liquid outlet pipe is open and immersed in the LNG liquid in the LNG vehicle gas cylinder, A liquid outlet shut-off valve is provided on the liquid outlet pipe outside the NG vehicle gas cylinder; one end of the first return air pipe is connected to the outlet of the external heat exchanger, and the other end of the first return air pipe is connected to the inlet of the high-speed pump; one end of the second return air pipe is connected to the outlet of the high-speed pump, and the other end of the second return air pipe extends into the bottom of the inner liner of the LNG vehicle gas cylinder, and when the gas cylinder is in use, the open end of the second return air pipe is immersed in the LNG liquid in the LNG vehicle gas cylinder, and a return air shut-off valve is provided on the second return air pipe located outside the LNG vehicle gas cylinder.
[0013] The third technical solution is to install an internal heat exchanger inside the LNG vehicle cylinder and an external heat exchanger outside the LNG vehicle cylinder. An external high-speed pump continuously extracts the fluid medium from the external heat exchanger. The internal heat exchanger is immersed in the LNG liquid, rapidly raising the temperature of the LNG liquid in the liner of the LNG vehicle cylinder, thereby increasing the LNG pressure in the cylinder to saturation pressure. At this time, the fluid medium, after absorbing the cold energy in the internal heat exchanger, exchanges heat with the cheap outside air through the external heat exchanger.
[0014] The specific solution is as follows: an internal heat exchanger is installed at the bottom of the inner liner of a horizontal LNG vehicle gas cylinder. The internal heat exchanger is immersed in the LNG liquid in the LNG vehicle gas cylinder when the gas cylinder is in use; an external heat exchanger and a high-speed pump are installed outside the LNG vehicle gas cylinder, and the high-speed pump is connected to the internal heat exchanger and the external heat exchanger through a piping system; the piping system includes: a first pipe, a second pipe, and a third pipe; the outlet of the high-speed pump is connected to the inlet of the internal heat exchanger through the first pipe, the outlet of the internal heat exchanger is connected to the inlet of the external heat exchanger through the second pipe, and the outlet of the external heat exchanger is connected to the inlet of the high-speed pump through the third pipe. The internal loop formed by the high-speed pump piping system, the internal heat exchanger, and the external heat exchanger is filled with a fluid medium, which can be air or other flowing medium.
[0015] Among them, high-speed pump refers to a pump with a higher speed. Generally, the speed of the pump is greater than 3600r / min. The high-speed pump has the advantages of high single-stage head, compact structure, easy maintenance and good reliability. The high-speed pump is used here because it can output high speed and large flow.
[0016] For ease of description, the pressure within the LNC vehicle gas cylinder is saturated to a gauge pressure of 0.8 MPa, referred to as the saturation pressure. All three of the aforementioned technical solutions utilize fully intelligent detection and control. The high-speed pump automatically starts when the cylinder pressure falls below the saturation pressure and automatically stops when the cylinder pressure reaches the saturation pressure, eliminating the need for manual driver operation. Specifically, the LNG vehicle gas cylinder is equipped with a cylinder pressure sensor to measure the pressure of the upper gas phase within the cylinder's liner. In both the first and third technical solutions, the cylinder pressure sensor's signal line and the high-speed pump's control signal line are connected to an intelligent control system. The intelligent control system controls the high-speed pump's operation based on data monitored by the cylinder pressure sensor. In the second technical solution, both the liquid discharge shut-off valve and the return gas shut-off valve utilize automatic control valves. The cylinder pressure sensor's signal line, the high-speed pump's control signal line, the liquid discharge shut-off valve's control signal line, and the return gas shut-off valve's control signal line are all connected to the intelligent control system. The intelligent control system controls the high-speed pump's operation, the liquid discharge shut-off valve's operation, and the return gas shut-off valve's operation based on data monitored by the cylinder pressure sensor.
[0017] Intelligent control systems are conventional control systems in the field of automated control, but there is currently no example of combining this control system with LNG cylinders. This combination of intelligent control systems and LNG cylinders to achieve automatic saturation function is unique.
[0018] In addition, heat exchangers include spiral plate heat exchangers, shell and tube heat exchangers, plate heat exchangers, stainless steel inner finned tube heat exchangers, etc. Since the stainless steel inner finned tube heat exchanger has the advantages of small size, light weight, low resistance, large heat exchange capacity, and sufficient heat exchange, and the three technical solutions described in the utility model use cheap air in the external environment, the heat exchange effect of the stainless steel inner finned tube heat exchanger has significant advantages over other forms of heat exchangers. Combined with a high-speed pump with a high speed and large flow rate, the gas cylinder can quickly reach the saturation pressure, maintain a steady supply of gas, and enable the natural gas engine to operate normally.
[0019] The beneficial effects of the present invention are: ① The first technical solution, the second technical solution, and the third technical solution all use cheap air to heat the LNG liquid in the LNG vehicle gas cylinder, and by increasing the temperature of the LNG liquid, the gas cylinder quickly reaches the saturation pressure, thereby achieving the purpose of meeting the 0.8 MPa gas supply pressure requirement of the natural gas engine; ② The form of heating the liquid phase space can also ensure that the liquid phase temperature and the gas phase temperature in the gas cylinder are relatively low, so that when the car is driving, the shaking and rocking of the gas cylinder will not cause secondary liquefaction and cause the gas cylinder pressure to decrease; ③ In conjunction with a high-speed pump with high speed and large flow, the gas cylinder can quickly reach the saturation pressure, maintain a steady supply of gas source, and enable the natural gas engine to operate normally. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a structural schematic diagram of the first technical solution of an LNG vehicle gas cylinder saturation device described in the utility model.
[0021] Figure 2 It is a structural schematic diagram of the second technical solution of the LNG vehicle gas cylinder saturation device described in the utility model.
[0022] Figure 3 It is a structural schematic diagram of the third technical solution of the LNG vehicle gas cylinder saturation device described in the utility model. DETAILED DESCRIPTION
[0023] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. Example 1
[0024] The LNG vehicle cylinder saturation device described in this embodiment is as follows: Figure 1 As shown, the apparatus comprises a horizontally placed LNG vehicle cylinder 1, with an internal heat exchanger 2 disposed at the bottom of the inner liner of the LNG vehicle cylinder 1. During use, the internal heat exchanger 2 is immersed in the LNG liquid within the LNG vehicle cylinder 1. In this embodiment, the internal heat exchanger 2 utilizes a stainless steel internal finned tube heat exchanger to enhance heat exchange efficiency.
[0025] The high-speed pump 3 is connected to the built-in heat exchanger 2 via a piping system comprising an inlet pipe 4 and an outlet pipe 5. One end of the inlet pipe 4 is connected to the outlet of the high-speed pump 3, located outside the LNG vehicle cylinder 1, and the other end is connected to the inlet of the built-in heat exchanger 2, which is in communication with the outside air. One end of the outlet pipe 5 is connected to the outlet of the built-in heat exchanger 2, and the other end extends outside the LNG vehicle cylinder 1. Both the outlet pipe 5 and the inlet pipe 4 span the interior of the cylinder liner and the exterior of the cylinder shell, passing through the cylinder mouth valve at the cylinder mouth.
[0026] In this embodiment, the LNG vehicle cylinder saturation device is further equipped with an intelligent control system 13. The LNG vehicle cylinder 1 is also provided with a cylinder pressure sensor 6 for measuring the pressure of the top gas phase space within the liner of the LNG vehicle cylinder 1. The signal line of the cylinder pressure sensor 6 and the control signal line of the high-speed pump 3 are both connected to the intelligent control system 13.
[0027] The working principle of the LNG vehicle gas cylinder saturation device described in this embodiment is: the intelligent control system 13 monitors the pressure value of the gas cylinder through the gas cylinder pressure sensor 6 to control whether the high-speed pump 3 is started. When the gas cylinder pressure is lower than the saturation pressure, the intelligent control system 13 controls the high-speed pump 3 to start, and continuously extracts air from the external environment through the high-speed pump 3, and sends the external air into the built-in heat exchanger 2, so that the LNG temperature in the LNG vehicle gas cylinder 1 rises rapidly. When the gas cylinder pressure sensor 6 monitors that the gas cylinder has reached the saturation pressure, the intelligent control system 13 controls the high-speed pump 3 to stop working.
[0028] In this embodiment, the end of the outlet pipe 5 extending from the LNG vehicle gas cylinder 1 is open and communicates with the outside air; in this case, the heat-exchanged air is directly discharged to the outside environment. In actual use, a valve can be provided on the outlet pipe 5 extending from the LNG vehicle gas cylinder 1.
[0029] In addition, the outlet pipe 5 extending out of the LNG vehicle gas cylinder 1 can also be connected to the inlet of the cold energy pipe of the equipment requiring cold energy to provide cold energy for these equipment requiring cold energy and achieve the purpose of cold energy recovery and utilization. Example 2
[0030] The LNG vehicle cylinder saturation device described in this embodiment is as follows: Figure 2 As shown, it comprises: an LNG vehicle gas cylinder 1, which is placed horizontally, and an external heat exchanger 7 is arranged outside the LNG vehicle gas cylinder 1. The high-speed pump 3 is connected to the external heat exchanger 7 through a pipeline system.
[0031] The piping system includes a liquid outlet pipe 8, a first gas return pipe 10, and a second gas return pipe 11. One end of the liquid outlet pipe 8 is connected to the inlet of the external heat exchanger 7, and the other end extends into the bottom of the inner liner of the LNG vehicle gas cylinder 1. When the cylinder is in use, the open end of the liquid outlet pipe 8, which extends into the inner liner of the LNG vehicle gas cylinder 1, is immersed in the LNG liquid in the LNG vehicle gas cylinder 1. A liquid outlet shut-off valve 9 is provided on the liquid outlet pipe 8, located outside the LNG vehicle gas cylinder 1. In this embodiment, the external heat exchanger 7 utilizes a stainless steel internal finned tube heat exchanger to improve heat exchange efficiency. One end of the first return air pipe 10 is connected to the outlet of the external heat exchanger 7, and the other end of the first return air pipe 10 is connected to the inlet of the high-speed pump 3. One end of the second return air pipe 11 is connected to the outlet of the high-speed pump 3, and the other end of the second return air pipe 11 extends into the bottom of the inner liner of the LNG vehicle gas cylinder 1. When the gas cylinder is in use, the open end of the second return air pipe is immersed in the LNG liquid in the LNG vehicle gas cylinder 1. A return air shut-off valve 12 is provided on the second return air pipe 11 located outside the LNG vehicle gas cylinder 1. The liquid outlet pipe 8 and the second return air pipe 11 both span the inside of the gas cylinder inner liner and the outside of the gas cylinder shell through the bottle mouth valve at the gas cylinder mouth.
[0032] In this embodiment, the LNG vehicle cylinder saturation device is further equipped with an intelligent control system 13. Both the liquid outlet shutoff valve 9 and the return air shutoff valve 12 are automatically controlled valves. The LNG vehicle cylinder 1 is also equipped with a cylinder pressure sensor 6 for measuring the pressure of the upper gas phase within the liner of the LNG vehicle cylinder 1. The signal lines of the cylinder pressure sensor 6, the control signal lines of the high-speed pump 3, the control signal lines of the liquid outlet shutoff valve 9, and the control signal lines of the return air shutoff valve 12 are all connected to the intelligent control system 13.
[0033] The working principle of the LNG vehicle gas cylinder saturation device described in this embodiment is as follows: the intelligent control system 13 monitors the gas cylinder pressure through the gas cylinder pressure sensor 6 to control whether the high-speed pump 3 is started or not. When the gas cylinder pressure is lower than the saturation pressure, the intelligent control system 13 controls the high-speed pump 3 to start and open the liquid outlet stop valve 9 and the return gas stop valve 12. The LNG liquid in the inner tank of the LNG vehicle gas cylinder 1 is continuously extracted by the high-speed pump 3, heated into saturated steam through the external heat exchanger 7, and sent back to the LNG liquid in the inner tank of the LNG vehicle gas cylinder 1 through the second return gas pipe 11, so that the LNG temperature in the inner tank of the LNG vehicle gas cylinder 1 rises rapidly. When the gas cylinder pressure sensor 6 detects that the gas cylinder has reached the saturation pressure, the intelligent control system 13 controls the high-speed pump 3 to stop working and close the liquid outlet stop valve 9 and the return gas stop valve 12. Example 3
[0034] The LNG vehicle cylinder saturation device described in this embodiment is as follows: Figure 3As shown, the apparatus comprises a horizontally positioned LNG vehicle gas cylinder 1, with an internal heat exchanger 2 disposed at the bottom of the inner liner of the LNG vehicle gas cylinder 1. During use, the internal heat exchanger 2 is immersed in the LNG liquid within the LNG vehicle gas cylinder 1. An external heat exchanger 7 and a high-speed pump 3 are disposed externally to the LNG vehicle gas cylinder 1. The high-speed pump 3 is connected to the internal heat exchanger 2 and the external heat exchanger 7 via a piping system. In this embodiment, the internal heat exchanger 2 and the external heat exchanger 7 utilize stainless steel internal finned tube heat exchangers to enhance heat exchange efficiency.
[0035] The piping system includes: a first pipe 14, a second pipe 15 and a third pipe 16. The outlet of the high-speed pump 3 is connected to the inlet of the built-in heat exchanger 2 through the first pipe 14, the outlet of the built-in heat exchanger 2 is connected to the inlet of the external heat exchanger 7 through the second pipe 15, and the outlet of the external heat exchanger 7 is connected to the inlet of the high-speed pump 3 through the third pipe 16. Among them, the first pipe 14 and the second pipe 15 are both spanned by the bottle mouth valve at the bottle mouth of the gas cylinder, inside the gas cylinder liner and outside the gas cylinder shell. The internal loop formed by the high-speed pump piping system, the built-in heat exchanger and the external heat exchanger is filled with a fluid medium, which can be air or other flowing media.
[0036] In this embodiment, the LNG vehicle cylinder saturation device is further equipped with an intelligent control system 13. The LNG vehicle cylinder 1 is also provided with a cylinder pressure sensor 6 for measuring the pressure of the top gas phase space within the liner of the LNG vehicle cylinder 1. The signal line of the cylinder pressure sensor 6 and the control signal line of the high-speed pump 3 are both connected to the intelligent control system 13.
[0037] The operating principle of the LNG vehicle cylinder saturation device described in this embodiment is as follows: the intelligent control system 13 monitors the cylinder pressure value via the cylinder pressure sensor 6 to control the activation of the high-speed pump 3. When the cylinder pressure is lower than the saturation pressure, the intelligent control system 13 controls the activation of the high-speed pump 3. The high-speed pump 3 continuously extracts the fluid medium from the external heat exchanger 7 and sends the fluid medium from the external heat exchanger 7 to the internal heat exchanger 2, causing the LNG temperature in the LNG vehicle cylinder 1 to rise rapidly. The fluid medium that has absorbed heat in the internal heat exchanger 2 returns to the external heat exchanger 7 and exchanges heat with the outside air through the external heat exchanger 7. At this time, the fluid medium in the pipeline system, the internal heat exchanger 2, and the external heat exchanger 7 forms an internal circulation. When the cylinder pressure sensor 6 detects that the cylinder has reached the saturation pressure, the intelligent control system 13 controls the high-speed pump 3 to stop.
[0038] In the aforementioned Examples 1, 2, and 3, inexpensive air is used to heat the LNG liquid in the LNG vehicle cylinder 1. By raising the temperature of the LNG liquid, the cylinder quickly reaches saturation pressure, thereby meeting the 0.8 MPa gas supply pressure requirement of the natural gas engine. Furthermore, heating the liquid phase space ensures that the liquid and gas phase temperatures within the cylinder are relatively low. Therefore, the swaying and shaking of the cylinder during vehicle operation prevents secondary liquefaction and a decrease in cylinder pressure. Finally, the use of a high-speed, high-flow pump 3 allows the cylinder to quickly reach saturation pressure, maintaining a continuous gas supply and enabling the normal operation of the natural gas engine.
[0039] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent change made based on the technical essence of the present invention shall still fall within the scope of protection required by the present invention.
Claims
1. A LNG vehicle cylinder saturation device, comprising: The LNG vehicle gas cylinder is characterized in that: a built-in heat exchanger is arranged at the bottom of the inner liner of the horizontal LNG vehicle gas cylinder, and the built-in heat exchanger is immersed in the LNG liquid in the LNG vehicle gas cylinder when the LNG vehicle gas cylinder is in use; a high-speed pump is arranged outside the LNG vehicle gas cylinder, and the high-speed pump is connected to the built-in heat exchanger through a pipeline system; The piping system includes: an air inlet pipe and an air outlet pipe; one end of the air inlet pipe is connected to the outlet of the high-speed pump, and the other end of the air inlet pipe is connected to the inlet of the built-in heat exchanger, and the inlet of the high-speed pump is connected to the outside air; one end of the air outlet pipe is connected to the outlet of the built-in heat exchanger, and the other end of the air outlet pipe extends out of the LNG vehicle gas cylinder.
2. The LNG vehicle cylinder saturation device according to claim 1 is characterized by: The built-in heat exchanger is a stainless steel internal fin tube heat exchanger.
3. The LNG vehicle cylinder saturation device according to claim 1 or 2, characterized in that: The open end of the gas outlet pipe extending out of the LNG vehicle gas cylinder is connected to the outside air; or the open end of the gas outlet pipe extending out of the LNG vehicle gas cylinder is connected to the inlet of the cold energy pipe of the equipment requiring cold energy.
4. The LNG vehicle cylinder saturation device according to claim 1 or 2, characterized in that: Also includes: Intelligent control system; a cylinder pressure sensor for measuring the pressure of the upper gas phase space in the inner liner of the LNG vehicle cylinder is also provided on the LNG vehicle cylinder; the signal line of the cylinder pressure sensor and the control signal line of the high-speed pump are both connected to the intelligent control system.
5. An LNG vehicle cylinder saturation device, comprising: The LNG vehicle gas cylinder is characterized in that: the LNG vehicle gas cylinder is placed horizontally, an external heat exchanger and a high-speed pump are arranged outside the LNG vehicle gas cylinder, and the high-speed pump is connected to the external heat exchanger through a pipeline system; The piping system includes: a liquid outlet pipe, a first air return pipe and a second air return pipe; one end of the liquid outlet pipe is connected to the inlet of an external heat exchanger, and the other end of the liquid outlet pipe extends into the bottom of the inner liner of the LNG vehicle gas cylinder, and when the LNG vehicle gas cylinder is in use, the end of the liquid outlet pipe is open and immersed in the LNG liquid in the LNG vehicle gas cylinder, and a liquid outlet stop valve is provided on the liquid outlet pipe located outside the LNG vehicle gas cylinder; one end of the first air return pipe is connected to the outlet of the external heat exchanger, and the other end of the first air return pipe is connected to the inlet of a high-speed pump; one end of the second air return pipe is connected to the outlet of the high-speed pump, and the other end of the second air return pipe extends into the bottom of the inner liner of the LNG vehicle gas cylinder, and when the LNG vehicle gas cylinder is in use, the end of the second air return pipe is open and immersed in the LNG liquid in the LNG vehicle gas cylinder, and a return stop valve is provided on the second air return pipe located outside the LNG vehicle gas cylinder.
6. The LNG vehicle cylinder saturation device according to claim 5, characterized in that: The external heat exchanger is a stainless steel internal fin tube heat exchanger.
7. The LNG vehicle cylinder saturation device according to claim 5 or 6, characterized in that: Also includes: Intelligent control system; the liquid outlet stop valve and the air return stop valve are both automatically controlled valves; a cylinder pressure sensor for measuring the pressure of the upper gas phase space in the inner liner of the LNG vehicle cylinder is also provided on the LNG vehicle cylinder; the signal line of the cylinder pressure sensor, the control signal line of the high-speed pump, the control signal line of the liquid outlet stop valve, and the control signal line of the air return stop valve are all connected to the intelligent control system.
8. An LNG vehicle cylinder saturation device, comprising: The LNG vehicle gas cylinder is characterized in that: an internal heat exchanger is arranged at the bottom of the inner liner of the horizontal LNG vehicle gas cylinder, and the internal heat exchanger is immersed in the LNG liquid in the LNG vehicle gas cylinder when the LNG vehicle gas cylinder is in use; an external heat exchanger and a high-speed pump are arranged outside the LNG vehicle gas cylinder, and the high-speed pump is connected to the internal heat exchanger and the external heat exchanger through a pipeline system; The pipeline system includes: a first pipeline, a second pipeline and a third pipeline; the outlet of the high-speed pump is connected to the inlet of the built-in heat exchanger through the first pipeline, the outlet of the built-in heat exchanger is connected to the inlet of the external heat exchanger through the second pipeline, and the outlet of the external heat exchanger is connected to the inlet of the high-speed pump through the third pipeline; the internal circulation formed by the high-speed pump pipeline system, the built-in heat exchanger and the external heat exchanger is filled with fluid medium.
9. The LNG vehicle cylinder saturation device according to claim 8, characterized in that: The external heat exchanger and the internal heat exchanger are both stainless steel internal fin tube heat exchangers.
10. The LNG vehicle cylinder saturation device according to claim 8 or 9, characterized in that: Also includes: Intelligent control system; a cylinder pressure sensor for measuring the pressure of the upper gas phase space in the inner liner of the LNG vehicle cylinder is also provided on the LNG vehicle cylinder; the signal line of the cylinder pressure sensor and the control signal line of the high-speed pump are both connected to the intelligent control system.