Jet device for improving precooling effect of vehicle-mounted liquid hydrogen tank

Abstract

The utility model belongs to the technical field of liquid hydrogen stations, and particularly relates to a spraying device for improving the precooling effect of a vehicle-mounted liquid hydrogen tank, which comprises a spraying inlet pipeline, a Laval spraying pipe, a spraying precooling pipeline and an atomizing nozzle, the outlet end of the spray inlet pipeline is connected with the inlet end of the Laval spray pipe, the outlet end of the Laval spray pipe is connected with the inlet end of the spray precooling pipeline, and a plurality of atomizing nozzles are uniformly distributed on the spray precooling pipeline. The multi-channel structure and the atomizing nozzle are adopted to improve the flow channel and the atomizing effect of fluid, the use effect is excellent, the high use and popularization value is achieved, and the multi-channel atomizing nozzle is suitable for large-scale storage tanks including but not limited to vehicle-mounted liquid hydrogen storage tanks and low-temperature liquid storage tanks.

Description

Technical Field

[0001] The utility model relates to an injection device for improving the pre-cooling efficiency of a vehicle-mounted liquid hydrogen tank, and is mainly used in the field of new energy, and relates to the application field of vehicle-mounted liquid hydrogen tanks. Background Art

[0002] Precooling on-board liquid hydrogen tanks is a key step in the commissioning process. The precooling nozzle is a core component that plays a key role in precooling on-board liquid hydrogen tanks. As liquid hydrogen tanks are increasingly used in civilian applications, storage tanks are also about to transform from large to small. Therefore, the precooling method of liquid hydrogen tanks is also changing from precooling large storage tanks to precooling small on-board liquid hydrogen tanks, and the precooling flow rate is also reduced. For small-volume on-board liquid hydrogen tanks, it is necessary to ensure the temperature drop rate, local temperature difference, and overall temperature difference during the precooling process, and the requirements for precooling nozzles are becoming increasingly higher.

[0003] Traditional nozzles are mainly used for pre-cooling large-volume liquid hydrogen storage tanks. Due to the large overall area, it is easy to cause insufficient and uneven pre-cooling and low pre-cooling efficiency. In order to consider the pre-cooling safety in the early stage of pre-cooling, liquid nitrogen is usually introduced for pre-cooling. Therefore, the pre-cooling injection pipe is filled with nitrogen, which is easy to cause gas-liquid blockage or backflow in the pre-cooling injection pipe, thereby affecting the initial pre-cooling effect.

[0004] In large-scale vehicle-mounted liquid hydrogen tanks, directional injection of a single nozzle is usually used, which will result in only a local pre-cooling nozzle blind area instead of the pre-cooling area, resulting in low pre-cooling efficiency. In addition, since a single nozzle is directly connected to the nozzle, it is easy for a single nozzle to cause nozzle blockage, thereby causing a deviation in the entire spray pipeline, causing liquid hydrogen or liquid nitrogen droplets that are not fully atomized to drip directly to the bottom of the tank, causing the temperature at this location to drop rapidly and the temperature difference with other locations to increase rapidly, resulting in the tank pre-cooling process being difficult to meet the corresponding temperature river speed, local temperature difference and overall temperature difference requirements. Utility Model Content

[0005] In view of the above problems, the purpose of the present utility model is to provide a vehicle-mounted liquid hydrogen tank injection device that can improve flow characteristics and enhance pre-cooling effect.

[0006] To achieve the above-mentioned purpose, the utility model adopts the following technical solution: a spray device applied to a small vehicle-mounted liquid hydrogen tank to improve the pre-cooling effect of the vehicle-mounted liquid hydrogen tank, comprising a spray inlet pipe, a Laval nozzle, a spray pre-cooling pipe, and an atomizing nozzle. The inlet end of the spray inlet pipe is connected to the vehicle-mounted liquid hydrogen tank, the outlet end of the spray inlet pipe is connected to the inlet end of the Laval nozzle, the outlet end of the Laval nozzle is connected to the inlet end of the spray pre-cooling pipe, and a plurality of atomizing nozzles are evenly distributed on the spray pre-cooling pipe.

[0007] Preferably, the spray inlet pipe is a cylindrical pipe with a length of 100 mm and a width of 20 mm. The front end of the Laval nozzle gradually shrinks toward the middle, and the middle gradually expands toward the rear end. The spray pre-cooling pipe is cylindrical, and 30-50 atomizing nozzles are arranged per square centimeter on the spray pre-cooling pipe. When spraying, it sprays around the inside of the liquid hydrogen tank, greatly enhancing the pre-cooling efficiency during pre-cooling.

[0008] In order to achieve heat preservation, the spray inlet pipe includes an inner liner, an insulation layer, a vacuum layer and an outer wall from the inside to the outside.

[0009] The atomizing nozzle adopts a fan-shaped outlet, and the central angle range of the fan-shaped outlet is controlled between 90° and 120°. Its main function is to increase its pre-cooling effect and the gas-liquid mixture will not cause the nozzle to be blocked.

[0010] In order to ensure the spraying effect, in a preferred embodiment of the present utility model, the atomizing nozzle includes a nozzle body, a gas-liquid diversion inlet, a tapered cavity, a jet section, an adjustable rolling joint and a nozzle outlet, the gas-liquid diversion inlet is arranged at the inlet end of the nozzle body, the tapered cavity is connected to the outlet end of the gas-liquid diversion inlet, and the diameter of the tapered cavity gradually decreases from one end close to the gas-liquid diversion inlet to the other end away from the gas-liquid diversion inlet, the jet section is connected to the outlet end of the tapered cavity, the diameter of the jet section is larger than the diameter of the outlet end of the tapered cavity, and the diameter of the jet section gradually decreases from one end close to the tapered cavity to the other end away from the tapered cavity, the nozzle outlet is arranged at the outlet end of the jet section, and the nozzle outlet is movably connected to the outlet end of the jet section through an adjustable rolling joint.

[0011] In order to increase the injection speed, a gas-liquid guide device is provided at the gas-liquid guide inlet, and the gas-liquid guide device includes a liquid guide inlet and multiple gas guide inlets. The gas guide inlets are evenly arranged along the circumference of the liquid guide inlet, and the diameter of the liquid guide inlet is larger than the diameter of the gas guide inlet.

[0012] Due to the adoption of the above technical solution, the utility model has the following characteristics:

[0013] 1. The utility model includes a spray pipe and a nozzle structure. By setting a structure of uniformly distributed internal liquid and gas diversion and a tapered section, the fluid characteristics are improved, the atomization effect is improved, and the cost-effectiveness is increased. It ensures that the pre-cooling nozzle can ensure the pre-cooling effect during the pre-cooling process and the initial stage of pre-cooling of a small vehicle-mounted liquid hydrogen tank.

[0014] 2. The utility model increases the speed by installing a Laval nozzle in the middle of the spray inlet pipe and the spray annular outlet pipe, thereby reducing the impact caused by insufficient initial velocity of the gas in the early stage of precooling, thereby increasing the adaptability of the working conditions of the later nozzle precooling.

[0015] 3. The utility model is provided with an adjustable rolling joint, which increases the direction of the rolling joint and increases the coverage of the spray by angle setting, thereby improving the overall spray effect. The design of the atomizing nozzle can increase the atomization effect of the spray and avoid the occurrence of dripping in the initial stage of pre-cooling.

[0016] In summary, the utility model adopts a multi-channel structure and an atomizing nozzle to improve the flow channel and atomization effect of the fluid, has excellent use effect, has high use and promotion value, and is suitable for large-scale storage tanks, including but not limited to vehicle-mounted liquid hydrogen storage tanks and cryogenic liquid storage tanks.

[0017] The significant advantages of this utility model are in the following aspects:

[0018] (1) The spray device as a whole adopts three structures: spray inlet pipe, Laval nozzle and spray pre-cooling pipe. The structure is novel, the pre-cooling efficiency is significantly improved, and no damage is caused to the structure.

[0019] (2) The inlet end of the overall pre-cooling structure adopts a vacuum layer pre-cooling pipeline, and its structure is mainly divided into the outer wall, the insulating vacuum layer and the inner liner. The insulating vacuum layer contains a variety of insulating materials for winding to ensure that the liquid hydrogen enters the pipeline for preliminary pre-cooling to produce a vaporization reaction to reduce its heat loss, thereby ensuring that the subsequent pre-cooling process can be completed efficiently in a short time, saving time and cost.

[0020] (3) The device is provided with a Laval nozzle in the middle of the spray inlet pipe and the spray pre-cooling pipe to transmit and accelerate the initial pre-cooling occurring in the spray inlet pipe, thereby avoiding the problem of gas-liquid retention in the traditional pre-cooling pipe due to the slow reaction in the late stage of pre-cooling.

[0021] (4) Considering the practicality of the Laval nozzle, the device is provided with a guide strip in the spray inlet pipe to transfer the liquid in the spray inlet pipe. The guide strip structure is set to pass through the Laval nozzle to the center body of the spray pre-cooling pipe. The gas directly enters the spray pre-cooling pipe and the nozzle inlet end through the Laval nozzle, so that the pre-cooling reaction occurs smoothly, eliminating the uncertainty of the Laval nozzle being applied to gas rather than liquid.

[0022] (5) The end of the device is set as a spray pre-cooling pipe, and a plurality of pre-cooling nozzles are arranged inside it. The size of the pre-cooling nozzles is 30-50 per square meter, which increases the pre-cooling contact area. In addition, since a central body is set inside to transmit liquid, the gas-liquid barrier and retention caused by the setting of multiple nozzles are reduced, thereby improving the pre-cooling efficiency.

[0023] (6) The pre-cooling nozzle is designed independently, so it eliminates the limitations of the traditional nozzle gas-liquid inlet. It directly enters the liquid through the guide strip and transmits the gas through the pipeline. The inner cavity of the nozzle is set to a structure that is wide in the front and narrow in the back. It can speed up the gas and liquid again in a small range. The method is relatively novel, and the nozzle mouth is set to a rolling spherical device and the central angle of the nozzle is set to 90°-120°, which increases the flexibility and efficiency of pre-cooling, thereby improving the pre-cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a side view of the injection device for improving the pre-cooling efficiency of the on-board liquid hydrogen tank of the utility model;

[0025] Figure 2 It is a side view of the Laval nozzle of the present utility model;

[0026] Figure 3 This is a cross-sectional view of the nozzle structure of the utility model;

[0027] Figure 4 It is a top view of the nozzle structure of the present utility model. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0029] like Figure 1 The shown embodiment is a spray device for improving the pre-cooling effect of a small vehicle-mounted liquid hydrogen tank, comprising a spray inlet pipe 1, a Laval nozzle 2, a spray pre-cooling pipe 3, and an atomizing nozzle 4. The inlet end of the spray inlet pipe 1 is connected to the vehicle-mounted liquid hydrogen tank, the outlet end of the spray inlet pipe 1 is connected to the inlet end of the Laval nozzle 2, the outlet end of the Laval nozzle 2 is connected to the inlet end of the spray pre-cooling pipe 3, and a plurality of atomizing nozzles 4 are evenly distributed on the spray pre-cooling pipe 3. The spray pipe (spray inlet pipe 1, Laval nozzle 2, spray pre-cooling pipe 3) is arranged 100 mm above the liquid inlet side of the horizontal vehicle-mounted liquid hydrogen tank, and several atomizing nozzles 4 are arranged in the spray pre-cooling pipe 3 for spraying the storage tank.

[0030] Specifically, the left side of the spray inlet pipe 1 is connected to the pre-cooling source, and can be directly extended from left to right to connect with the inlet section 5 of the Laval nozzle 2, and the right outlet section 6 of the Laval nozzle 2 can be directly connected to the inlet of the spray pre-cooling pipe 3, wherein the spray inlet pipe 1, the Laval nozzle 2 and the spray pre-cooling pipe 3 are all on the same horizontal line, and the horizontal position is about 10 cm above the liquid inlet side of the horizontal vehicle-mounted liquid hydrogen tank. When in use, liquid nitrogen or liquid hydrogen enters the Laval nozzle 2 through the spray inlet pipe 1 for pressurization and speed increase, and then the gas and liquid are separated by the guide strip. After separation, the gas and liquid enter the spray pre-cooling pipe 3 and reach the atomizing nozzle 4 for spray pre-cooling.

[0031] like Figure 2 The Laval nozzle 2 shown includes an inlet section 5 and an outlet section 6. The liquid flowing in through the spray inlet pipe 1 directly passes through the Laval nozzle 2 through the guide strip and enters the liquid guide inlet 15. The gas generated after the initial pre-cooling reaction flows into the inlet section 5 of the Laval nozzle 2 due to the increased pressure after the reaction, passes through the narrow throat of the front half to increase speed and pressurize, and finally escapes from the rear half of the Laval nozzle 2. Since the gas and liquid are accelerated during the equal-height flow, the pressure around them becomes smaller due to the increase in speed, so that the gas and liquid enter the nozzle more quickly, thereby achieving a basic pre-cooling initial velocity.

[0032] like Figure 3 、 4As shown, the atomizing nozzle includes a nozzle body 11, a gas-liquid guide inlet 7, a tapered cavity 8, a jet section 9, an adjustable rolling joint 10 and a nozzle outlet 12. A gas-liquid guide device 13 is provided inside the nozzle body 11, and the gas-liquid guide device includes a liquid guide inlet 15 and a plurality of gas guide inlets 14. The gas guide inlet 14 is evenly arranged along the circumference of the liquid guide inlet 15, and the diameter of the liquid guide inlet 15 is larger than the diameter of the gas guide inlet 14. A molecular film is provided at the gas-liquid guide device and the gas-liquid guide inlet 7 to facilitate the entry of gas and liquid without turbulence. Liquid nitrogen and liquid hydrogen fluids enter through the liquid guide inlet 15, and nitrogen and hydrogen both enter the tapered cavity through the gas guide inlet 14. The purpose of providing multiple gas guide inlets 14 is to allow the gas-liquid mixture to have A larger initial velocity is achieved, thereby reducing the retention of gas and liquid in the nozzle body. By controlling the tapered cavity 8, the shear force of the surrounding gas is enhanced, and the atomization effect of the nozzle is enhanced. The length and diameter of the tapered cavity 8 are controlled within the set range. The diameter of the tapered cavity 8 gradually decreases from one end close to the gas-liquid diversion inlet 7 to the other end away from the gas-liquid diversion inlet 7. The length of the tapered cavity should take into account the size of the overall nozzle, so it should not be too long. If it is too long, the chemical properties of the gas and liquid will affect its flow loss and reduce the flow coefficient of the nozzle. Therefore, the smaller the diameter of the tapered cavity 8, the smaller the outlet area at the same liquid nitrogen or liquid hydrogen flow rate, the greater the difference in pressure between the internal and external liquid nitrogen or liquid hydrogen, the faster the liquid nitrogen or liquid hydrogen is ejected, the stronger the shear force formed by the gas around the nozzle, and the better the atomization effect.

[0033] The outlet of the tapered cavity 8 is sequentially connected to the jet section 9, the adjustable rolling joint 10, and the nozzle outlet 12. The adjustable rolling joint 10 can be adjusted before installation to meet the requirements of the corresponding process parameters and pre-cooling scheme. Specifically, the adjustable rolling joint 10 is used to adjust the spray angle before the nozzle is installed. The spray angle is adjusted based on actual process parameters such as flow rate, pressure, and temperature, and pre-cooling schemes such as liquid nitrogen pre-cooling or liquid hydrogen pre-cooling. This enhances the nozzle spray coverage and improves the uniformity of the temperature drop during tank pre-cooling. After passing through the tapered cavity 8, the liquid nitrogen or liquid hydrogen fluid passes through the jet section 9 and the adjustable rolling joint 10 and enters the nozzle outlet 12.

[0034] Furthermore, the nozzle outlet 12 can be fan-shaped, and the fan height can be used to control the atomization effect of the liquid hydrogen pre-cooling. After the liquid passes through the fan-shaped outlet, it forms a uniform and flat fan-shaped liquid surface with good symmetry. The center angle of the fan-shaped outlet and the angle of the liquid fan-shaped liquid surface are interrelated. By controlling the center angle, the angle of the fan-shaped liquid surface can be controlled to enhance the atomization effect of the liquid hydrogen or liquid nitrogen. Furthermore, the center angle of the fan-shaped outlet is between 90° and 120°, and the fan height can also be controlled by pressure to enhance the atomization effect of the liquid hydrogen or liquid nitrogen.

[0035] Liquid nitrogen or liquid hydrogen fluid is separated into gas and liquid through the guide strips in the spray pipe and finally enters the Laval nozzle 2. The gas entering the Laval nozzle 2 will gain a higher speed and enter the atomizing nozzle 4 of the spray pre-cooling pipe 3, while the liquid directly enters the inner cavity of the spray pre-cooling pipe 3 through the guide strips to mix with the gas and enter the nozzle for reaction pre-cooling. A gas-liquid guide device is provided in the nozzle body, which is used to introduce gas and liquid, and each inlet of the gas-liquid guide device is connected to the tapered cavity 8, and the outlet end of the tapered cavity 8 can be connected to the adjustable rolling joint 10 and the nozzle outlet 12 through a connecting pipe. Therefore, the utility model can enable the storage tank to fully exert its pre-cooling efficiency in the early stage of pre-cooling, making the entire pre-cooling process faster and saving costs.

[0036] Finally, it should be noted that while the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the specific embodiments described above, which are merely illustrative and non-restrictive. It will be apparent to those skilled in the art that other variations or modifications may be made without departing from the spirit and scope of the present invention and the claims, and all such variations and modifications are within the scope of protection of the present invention.

Claims

1. A spray device for improving the pre-cooling effect of a vehicle-mounted liquid hydrogen tank, characterized by: It includes a spray inlet pipe, a Laval nozzle, a spray pre-cooling pipe, and an atomizing nozzle. The inlet end of the spray inlet pipe is connected to the on-board liquid hydrogen tank, the outlet end of the spray inlet pipe is connected to the inlet end of the Laval nozzle, the outlet end of the Laval nozzle is connected to the inlet end of the spray pre-cooling pipe, and a plurality of atomizing nozzles are evenly distributed on the spray pre-cooling pipe.

2. The injection device for improving the pre-cooling effect of the on-board liquid hydrogen tank according to claim 1 is characterized in that: The spray inlet pipe is a cylindrical pipe with a length of 100 mm and a width of 20 mm.

3. The injection device for improving the pre-cooling effect of the on-board liquid hydrogen tank according to claim 2 is characterized in that: The front end of the Laval nozzle gradually contracts toward the middle portion, and the middle portion gradually expands toward the rear end.

4. The injection device for improving the pre-cooling effect of the on-board liquid hydrogen tank according to claim 3 is characterized in that: The spray pre-cooling pipe is cylindrical, and 30-50 atomizing nozzles are arranged per square centimeter on the spray pre-cooling pipe.

5. The injection device for improving the pre-cooling effect of the on-board liquid hydrogen tank according to claim 2 is characterized in that: The spray inlet pipe comprises an inner liner, an insulation layer, a vacuum layer and an outer wall in sequence from the inside out.

6. The injection device for improving the pre-cooling effect of a vehicle-mounted liquid hydrogen tank according to claim 1 is characterized in that: The atomizing nozzle adopts a fan-shaped outlet, and the central angle range of the fan-shaped outlet is controlled between 90° and 120°.

7. The injection device for improving the pre-cooling effect of the on-board liquid hydrogen tank according to claim 6 is characterized in that: The atomizing nozzle includes a nozzle body, a gas-liquid diversion inlet, a tapered cavity, a jet section, an adjustable rolling joint and a nozzle outlet, wherein the gas-liquid diversion inlet is arranged at the inlet end of the nozzle body, the tapered cavity is connected to the outlet end of the gas-liquid diversion inlet, and the diameter of the tapered cavity gradually decreases from one end close to the gas-liquid diversion inlet to the other end away from the gas-liquid diversion inlet, the jet section is connected to the outlet end of the tapered cavity, the diameter of the jet section is larger than the diameter of the outlet end of the tapered cavity, and the diameter of the jet section gradually decreases from one end close to the tapered cavity to the other end away from the tapered cavity, the nozzle outlet is arranged at the outlet end of the jet section, and the nozzle outlet is movably connected to the outlet end of the jet section through an adjustable rolling joint.

8. The injection device for improving the pre-cooling effect of the on-board liquid hydrogen tank according to claim 7 is characterized in that: A gas-liquid guide device is provided at the gas-liquid guide inlet, and the gas-liquid guide device includes a liquid guide inlet and multiple gas guide inlets. The gas guide inlets are evenly arranged along the circumference of the liquid guide inlet, and the diameter of the liquid guide inlet is larger than the diameter of the gas guide inlet.

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