A deep cooling separation hydrogen gas device with liquid nitrogen circulating refrigeration

Abstract

The utility model provides a kind of liquid nitrogen circulation refrigeration's cryogenic separation hydrogen gas device, including heat exchanger body, heat exchanger body includes upper head, cylinder and lower head connected in turn, cylinder one side is equipped with support leg, gas outlet, observation port, gas phase discharge port and first remote liquid level meter port are set on upper head, cylinder upper portion is equipped with gas material inlet pipe;Cylinder inside is provided with multiple spiral tubes along its length direction, and multiple spiral tubes are layered with coaxial mode, the diameter of adjacent heat exchange tube is increasing or decreasing distribution, the upper port of multiple heat exchange tubes is connected with gas nitrogen outlet pipe, the lower port of multiple heat exchange tubes is connected with liquid nitrogen inlet pipe.The fluid in the spiral tube of the utility model is under the action of centrifugal force, enhances the disturbance of fluid boundary layer, heat exchange boundary layer, makes boundary layer thin, strengthens convection heat exchange;And impurity in fluid is easily taken away, to some extent, solve the problem such as heat exchanger blockage caused by impurity precipitation in fluid.

Description

Technical Field

[0001] This utility model relates to the field of heat exchanger technology, specifically to a cryogenic hydrogen gas separation device using liquid nitrogen circulation refrigeration. Background Technology

[0002] A heat exchanger is an energy-saving device that enables heat transfer between two or more fluids at different temperatures. It transfers heat from a higher-temperature fluid to a lower-temperature fluid, bringing the fluid temperature to the specified parameters of the process to meet the requirements of the process conditions. It is also one of the main devices for improving energy utilization efficiency.

[0003] In a heat exchanger, liquid nitrogen flows through the tube side and gaseous material flows through the shell side, exchanging heat between the two. The liquid nitrogen is used to cryogenically liquefy the material. However, existing heat exchangers are shell-and-tube type, with mostly straight tubes inside, resulting in limited surface area, poor heat exchange efficiency, and a narrow suitable gas flow range. Furthermore, impurities in the fluid are prone to precipitating and causing blockages in the heat exchanger. Utility Model Content

[0004] To address the technical problems existing in the background art, this utility model provides a cryogenic hydrogen gas separation device using liquid nitrogen circulation refrigeration.

[0005] The technical solution of this utility model is as follows:

[0006] A cryogenic hydrogen gas separation device with liquid nitrogen circulation refrigeration includes a heat exchanger body, which includes an upper end cap, a cylinder and a lower end cap connected in sequence. A support leg is provided on one side of the cylinder. A gas outlet, an observation port, a gas phase discharge port and a first remote liquid level gauge port are provided on the upper end cap. A gas material inlet pipe is provided at the upper part of the cylinder.

[0007] The cylinder has multiple spiral tubes arranged along its length, and these spiral tubes are nested coaxially. The diameters of adjacent heat exchange tubes are distributed in an increasing or decreasing manner. The upper ends of the heat exchange tubes are connected through gas nitrogen outlet pipes, and the lower ends of the heat exchange tubes are connected through liquid nitrogen inlet pipes. The liquid nitrogen inlet pipe is connected to an external liquid nitrogen storage tank, and the gas nitrogen outlet pipe is connected to an external liquid separator and nitrogen system.

[0008] One end of the gas material inlet pipe is located on the outside of the cylinder, and the other end extends downward in a vertical direction to the inside of the innermost spiral tube.

[0009] The lower end cap is equipped with a liquid return pipe and a second remote level gauge port that is compatible with the first remote level gauge port.

[0010] To prevent damage to the equipment and potential safety hazards caused by excessive pressure from liquid nitrogen vaporization, a safety valve is installed on the section of the gas nitrogen outlet pipe located on the outside of the cylinder.

[0011] Preferably, the lower end cap is equipped with a remote thermometer port.

[0012] To facilitate the installation of multiple helical tubes within the shell and increase the heat exchange area, adjacent helical tubes rotate in opposite directions. Specifically, by generating secondary flows in opposite directions that collide and shear each other, the fluid turbulence is significantly enhanced, and the heat transfer boundary layer is disrupted. This results in a substantial increase in the heat transfer coefficients of both the tube side and the shell side, greatly improving the overall heat exchange efficiency. Simultaneously, it also improves the uniformity of fluid distribution, reduces dead zones, and may incidentally reduce fouling tendency and potential equilibrium vibrations.

[0013] The installation structure of the spiral tube is such that the spiral tube is detachably connected to the inner wall of the cylinder through multiple fixed supports, which are arranged vertically.

[0014] The specific structure of the aforementioned fixing bracket is as follows: the fixing bracket includes an upper clamping plate and a lower clamping plate that are fastened together. Both the upper clamping plate and the lower clamping plate are provided with multiple arched sections that are adapted to the spiral tube along their length direction. The upper clamping plate and the lower clamping plate are detachably connected by multiple connectors.

[0015] Furthermore, the arched section of the upper clamping plate and the arched section of the lower clamping plate form a support channel for the spiral tube, and the diameter of the support channel is 0.5-1.5cm larger than the outer diameter of the spiral tube.

[0016] Preferably, the outlet height of the gas material inlet pipe is located between 1 / 3 and 2 / 3 of the cylinder height.

[0017] The beneficial effects of this utility model are as follows:

[0018] Under the action of centrifugal force, the fluid in the spiral tube exhibits a three-dimensional network flow or an irregular spiral flow, which enhances the disturbance of the fluid boundary layer and the heat transfer boundary layer, thins the boundary layer, and strengthens convective heat transfer. Moreover, under the action of centrifugal force, impurities in the fluid are easily carried away, which has a self-cleaning function and avoids frequent cleaning. To a certain extent, it solves the problems of heat exchanger blockage and reduced heat exchange efficiency caused by the precipitation of impurities in the fluid.

[0019] The straight liquid nitrogen pipes inside the heat exchanger body are replaced with multiple spiral tubes (the actual number is determined based on the size of the cryogenic chamber and the pipe diameter). Firstly, the surface area of ​​the spiral tubes increases dramatically, increasing the heat exchange area between the refrigerant liquid nitrogen and the heat transfer medium, thus improving the heat exchange effect and significantly enhancing the cryogenic effect. Secondly, the spiral tubes can reduce expansion, decrease or eliminate stress, and protect internal components. Thirdly, the pressure resistance of the liquid nitrogen pipes is increased, improving their pressure resistance and safety performance.

[0020] The cryogenic effect is significant. After cryogenic cooling with liquid nitrogen, the chlorosilanes in the mixed gas can be completely liquefied and thoroughly separated from the hydrogen. The separated hydrogen does not contain chlorosilane components after testing. Due to the significant cryogenic effect, the separation rate is accelerated and the gas feed flow rate is increased.

[0021] The inner wall of the heat exchanger body is equipped with a fixing plate for fixing the spiral tube, ensuring that the spiral tube does not deform or move under the extremely cold conditions of liquid nitrogen, thus providing better fixation. The fixing plate has a support channel for fixing the coil. The spiral tube passes through the support channel. The diameter of the support channel is slightly larger than that of the coil, which can accommodate the deformation of the spiral tube under stress and leave a certain gap to protect the spiral tube. The fixing plate can better fix the spiral tube, maintain the original shape of the spiral tube, and better exert the deep cryogenic effect. Attached Figure Description

[0022] In the attached diagram:

[0023] Figure 1 This is a schematic diagram of the cross-sectional structure;

[0024] Figure 2 for Figure 1 Enlarged structural diagram at point A in the middle;

[0025] Figure 3 This is a schematic diagram of a spiral tube structure;

[0026] Figure 4 This is a front view of a spiral tube;

[0027] Figure 5 This is a top view of a spiral tube.

[0028] Figure 6 This is a schematic diagram of the fixed support structure;

[0029] Figure 7 This is a schematic diagram of the heat exchanger body structure;

[0030] The components represented by the various reference numerals in the diagram are:

[0031] 1. Heat exchanger body; 101. Upper head; 102. Shell; 103. Lower head; 2. Gas outlet; 3. Observation port; 4. Gas phase outlet; 5. First remote liquid level gauge port; 6. Second remote liquid level gauge port; 7. Gas material inlet pipe; 8. Spiral pipe; 9. Liquid nitrogen inlet pipe; 10. Gas nitrogen outlet pipe; 11. Liquid reflux pipe; 12. Safety valve; 13. Remote thermometer port; 14. Fixed bracket; 1401. Upper clamping plate; 1402. Lower clamping plate; 1403. Arched section; 1404. Support channel; 15. Connecting parts; 16. Support legs. Detailed Implementation

[0032] See Figure 1 and Figure 7 As shown, a cryogenic hydrogen gas separation device using liquid nitrogen circulation refrigeration includes a heat exchanger body 1. The heat exchanger body 1 includes an upper end cap 101, a cylinder 102, and a lower end cap 103 connected in sequence. A support leg 16 is provided on one side of the cylinder 102. The upper end cap 101 is provided with a gas outlet 2, an observation port 3, a gas phase discharge port 4, and a first remote liquid level gauge port 5. A gas material inlet pipe 7 is provided at the upper part of the cylinder 102. The gas outlet 2 is used to discharge the separated hydrogen gas.

[0033] See Figure 2 and Figure 3 As shown, multiple spiral tubes 8 are arranged along the length of the cylinder 102, and these spiral tubes 8 are coaxially nested. The diameters of adjacent heat exchange tubes are distributed in an increasing or decreasing manner. The upper ends of the heat exchange tubes are connected through a gas nitrogen outlet pipe 10, and the lower ends are connected through a liquid nitrogen inlet pipe 9. The liquid nitrogen inlet pipe 9 is connected to an external liquid nitrogen storage tank, and the gas nitrogen outlet pipe 10 is connected to an external separator and nitrogen system. The gas flowing out of the gas nitrogen outlet pipe 10 may contain residual liquid nitrogen. The separator separates the gas and liquid. The separated nitrogen enters the nitrogen system to provide a gas source for purging, pressurization, and emergency gas protection of the device. The separated liquid nitrogen is then returned to the liquid nitrogen storage tank system for backup. To prevent damage to the equipment due to overpressure caused by liquid nitrogen vaporization and potential safety hazards, a safety valve 12 is installed on the section of the gas nitrogen outlet pipe 10 located outside the cylinder 102.

[0034] One end of the gas material inlet pipe is located on the outside of the cylinder 102, and the other end extends vertically downward to the inside of the innermost spiral pipe 8. The outlet height of the gas material inlet pipe is between 1 / 3 and 2 / 3 of the height of the cylinder 102.

[0035] See Figure 1 and Figure 7 As shown, the lower end cap 103 is equipped with a liquid reflux pipe 11 and a second remote liquid level gauge port 6 adapted to the first remote liquid level gauge port 5. The lower end cap 103 is equipped with a remote thermometer port 13. The material gas enters the cylinder 102 of the heat exchanger body from top to bottom, the non-condensable gas is discharged from the gas phase outlet 4, and the liquid phase flows out from the liquid reflux pipe 11.

[0036] To facilitate the installation of multiple spiral tubes 8 within the shell 102 and increase the heat exchange area, adjacent spiral tubes 8 rotate in opposite directions. Specifically, by generating secondary flows in opposite directions that collide and shear each other, the fluid turbulence is significantly enhanced, and the heat transfer boundary layer is disrupted, thereby significantly improving the heat transfer coefficients of both the tube side and shell side, and greatly enhancing the overall heat exchange efficiency. Simultaneously, it also improves the uniform distribution of the fluid, reduces dead zones, and may incidentally reduce fouling tendency and potential equilibrium vibration.

[0037] Under the action of centrifugal force, the fluid in the spiral tube 8 exhibits a three-dimensional network flow or an irregular spiral flow, which enhances the disturbance of the fluid boundary layer and the heat exchange boundary layer, thins the boundary layer, and strengthens convective heat transfer. Moreover, under the action of centrifugal force, impurities in the fluid are easily carried away, which has a self-cleaning function and avoids frequent cleaning. To a certain extent, it solves the problems of heat exchanger blockage and reduced heat exchange efficiency caused by the precipitation of impurities in the fluid.

[0038] The installation structure of the spiral tube 8 is such that the spiral tube 8 is detachably connected to the inner wall of the cylinder 102 via multiple fixed brackets 14, which are arranged vertically. Each fixed bracket 14 includes an upper clamping plate 1401 and a lower clamping plate 1402 that are interlocked vertically. Both the upper clamping plate 1401 and the lower clamping plate 1402 are provided with multiple arched sections 1403 along their length that are adapted to the spiral tube 8. The upper clamping plate 1401 and the lower clamping plate 1402 are detachably connected via multiple connectors 15.

[0039] The arched section 1403 of the upper clamping plate 1401 and the arched section 1403 of the lower clamping plate 1402 form a support channel 1404 for supporting the spiral tube 8. The diameter of the support channel 1404 is 0.5-1.5cm larger than the outer diameter of the spiral tube 8.

[0040] In the above structure, the inner wall of the cylinder 102 of the heat exchanger body 1 is equipped with a fixing plate for fixing the spiral tube 8, which ensures that the spiral tube 8 does not deform or move under the extremely cold conditions of liquid nitrogen, and plays a better fixing role. The fixing plate is provided with a support channel 1404 for fixing the coil. The spiral tube 8 passes through the support channel 1404. The diameter of the support channel 1404 is slightly larger than that of the coil, which can leave a certain gap to accommodate the deformation of the spiral tube 8 under stress, thus protecting the spiral tube 8. The fixing plate can better fix the spiral tube 8, ensure the original shape of the spiral tube 8, and better exert the deep cryogenic effect.

[0041] A mixture of chlorosilanes (silane, silane, and propane) and hydrogen enters the cylinder of the heat exchanger body through the gas material inlet pipe. Liquid nitrogen is present inside the spiral tube. Under the action of the liquid nitrogen, the chlorosilane mixture (silane, silane, and propane) is condensed and liquefied after passing through the heat exchanger. The liquid nitrogen temperature is -196℃, the boiling point of hydrogen is -252.87℃, the boiling point of silane is -112℃, the boiling point of silane is -14.3℃, and the boiling point of propane is 53℃. The spiral tube arrangement, within a limited space, provides a higher heat exchange area, resulting in a higher heat transfer coefficient and better heat exchange efficiency. Testing shows that the non-condensable gas discharged from the top does not contain chlorosilane or hydrogen components. A gas-liquid separator is connected after the cryogenic unit; the separated hydrogen does not contain chlorosilane components, resulting in better cryogenic separation and higher efficiency.

Claims

1. A cryogenic hydrogen gas separation device using liquid nitrogen circulation refrigeration, comprising a heat exchanger body (1), the heat exchanger body (1) comprising an upper end cap (101), a cylinder (102), and a lower end cap (103) connected in sequence, wherein a support leg (16) is provided on one side of the cylinder (102), characterized in that, The upper end cap (101) is provided with a gas outlet (2), an observation port (3), a gas phase discharge port (4) and a first remote liquid level gauge port (5), and the upper part of the cylinder (102) is provided with a gas material inlet pipe (7); The cylinder (102) has multiple spiral tubes (8) arranged along its length, and the multiple spiral tubes (8) are coaxially nested in layers. The diameters of adjacent heat exchange tubes are distributed in an increasing or decreasing manner. The upper ends of the multiple heat exchange tubes are connected through a gas nitrogen outlet pipe (10), and the lower ends of the multiple heat exchange tubes are connected through a liquid nitrogen inlet pipe (9). The liquid nitrogen inlet pipe (9) is connected to an external liquid nitrogen storage tank, and the gas nitrogen outlet pipe (10) is connected to an external liquid separator and nitrogen system. One end of the gas material inlet pipe is located outside the cylinder (102), and the other end extends downward in the vertical direction to the inside of the innermost spiral tube (8); The lower end cap (103) is provided with a liquid return pipe (11) and a second remote liquid level gauge port (6) adapted to the first remote liquid level gauge port (5).

2. The cryogenic hydrogen gas separation device using liquid nitrogen circulation refrigeration according to claim 1, characterized in that, The section of the gas nitrogen outlet pipe (10) located outside the cylinder (102) is equipped with a safety valve (12).

3. The cryogenic hydrogen gas separation device using liquid nitrogen circulation refrigeration according to claim 1, characterized in that, The lower end cap (103) is equipped with a remote thermometer port (13).

4. The cryogenic hydrogen gas separation device using liquid nitrogen circulation refrigeration according to claim 1, characterized in that, The adjacent spiral tubes (8) have opposite directions of rotation.

5. The cryogenic hydrogen gas separation device using liquid nitrogen circulation refrigeration according to claim 1, characterized in that, The spiral tube (8) is detachably connected to the inner wall of the cylinder (102) through multiple fixed supports (14), which are arranged vertically.

6. The cryogenic hydrogen gas separation device using liquid nitrogen circulation refrigeration according to claim 5, characterized in that, The fixed bracket (14) includes an upper clamping plate (1401) and a lower clamping plate (1402) that are fastened together. The upper clamping plate (1401) and the lower clamping plate (1402) are provided with multiple arched sections (1403) that are adapted to the spiral tube (8) along their length direction. The upper clamping plate (1401) and the lower clamping plate (1402) are detachably connected by multiple connectors (15).

7. The cryogenic hydrogen gas separation device using liquid nitrogen circulation refrigeration according to claim 6, characterized in that, The arched section (1403) of the upper clamping plate (1401) and the arched section (1403) of the lower clamping plate (1402) form a support channel (1404) for supporting the spiral tube (8). The diameter of the support channel (1404) is 0.5-1.5 cm larger than the outer diameter of the spiral tube (8).

8. The cryogenic hydrogen gas separation device using liquid nitrogen circulation refrigeration according to claim 1, characterized in that, The outlet height of the gas material inlet pipe is located between 1 / 3 and 2 / 3 of the height of the cylinder (102).

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