Liquid nitrogen gasification device and cold energy recovery system

Abstract

The application provides a liquid nitrogen gasification device and a cold energy recovery system. The liquid nitrogen gasification device shell comprises a side wall and oppositely arranged top and bottom plates, and the side wall, the top plate and the bottom plate form a closed cavity. The shell is provided with a liquid nitrogen inlet and a nitrogen outlet, and a medium inlet and a medium outlet. A first gasification pipe is arranged in the cavity and is arranged in a spiral shape. The inlet end of the first gasification pipe is communicated with the liquid nitrogen inlet. A second gasification pipe is arranged in the cavity and is spirally wound on the outer wall of the first gasification pipe. The outlet end of the second gasification pipe is communicated with the nitrogen outlet. A connecting piece is arranged to communicate the outlet end of the first gasification pipe with the inlet end of the second gasification pipe. The first gasification pipe and the second gasification pipe prolong the time of liquid nitrogen in the gasification device, improve the gasification efficiency, and the medium is introduced to improve the cold energy recovery efficiency.

Description

Technical Field

[0001] This invention relates to the field of liquid nitrogen vaporization technology, specifically to a liquid nitrogen vaporization device and a cold energy recovery system. Background Technology

[0002] Liquid nitrogen (LN2) is an important cryogenic industrial gas with broad application prospects in many fields, including semiconductor manufacturing. Liquid nitrogen has a boiling point of -196℃, and its transformation from liquid to gas requires the absorption of a large amount of heat; its latent heat of vaporization is approximately 199 kJ / kg. In practical industrial applications, liquid nitrogen is usually stored and transported in liquid form, and needs to be converted into gaseous nitrogen by a vaporizer before use in downstream equipment. Currently, liquid nitrogen vaporizers are mainly divided into two categories: ambient temperature type and water bath type, but some technical shortcomings still exist.

[0003] For example, in existing ambient air vaporizers, the vaporization tubes typically use straight tubes or simple coil structures. The liquid nitrogen flows relatively short within the tubes, resulting in insufficient residence time and a limited heat exchange area. This causes the liquid nitrogen to fail to fully absorb heat before being discharged from the outlet, with some liquid nitrogen entrained in the nitrogen gas and entering downstream pipelines, leading to energy waste and potentially adversely affecting the normal operation of downstream gas-using equipment. Furthermore, using single or multiple parallel pipelines makes it difficult to achieve a longer heat exchange path and sufficient heat exchange within a limited space, resulting in a low heat exchange rate per unit volume.

[0004] Secondly, severe frost and ice formation on the vaporizer surface in low-temperature environments has long been a technical problem in this field. When an ambient air vaporizer is in operation, due to the extremely low temperature inside the tube and the significant temperature difference with the environment, water vapor in the air will quickly condense on the outer wall of the vaporization tube to form a frost layer, which greatly reduces the heat exchange area. To ensure normal operation, it is often necessary to frequently shut down for defrosting or to configure additional auxiliary heating devices, which greatly increases the operating and maintenance costs and energy consumption, and may even force a switch to a steam hot water bath vaporizer to ensure continuous gas supply.

[0005] Furthermore, the problem of wasted cooling capacity in existing heat exchange system designs cannot be ignored. The vaporization process of liquid nitrogen is accompanied by a violent endothermic reaction, absorbing a large amount of heat from the environment or heat source. Inevitably, a large amount of cooling capacity is lost into the environment and is not effectively utilized, resulting in energy waste. Summary of the Invention

[0006] In view of the problems existing in the liquid nitrogen vaporizers in the prior art described above, this application provides a liquid nitrogen vaporization device and a cold energy recovery system to solve the problems of low vaporization efficiency and low cold energy recovery efficiency in the prior art.

[0007] To achieve the above and other related objectives, the present invention provides a liquid nitrogen vaporization apparatus, comprising:

[0008] The outer casing includes side walls and a top plate and a bottom plate disposed opposite to each other, the side walls forming a sealed chamber with the top plate and the bottom plate; the outer casing is provided with a liquid nitrogen inlet and a nitrogen outlet, as well as a medium inlet and a medium outlet;

[0009] The first vaporization tube is located in the chamber. The first vaporization tube is arranged in a spiral shape, and the inlet end of the first vaporization tube is connected to the liquid nitrogen inlet.

[0010] The second vaporization tube is located in the chamber. The second vaporization tube is spirally wound around the outer wall of the first vaporization tube. The outlet end of the second vaporization tube is connected to the nitrogen outlet.

[0011] A connector connects the outlet end of the first vaporization pipe to the inlet end of the second vaporization pipe.

[0012] Optionally, the first vaporization tube is arranged coaxially on the central axis of the shell in the form of a cylindrical helix; the second vaporization tube is wound in the opposite direction to the helix direction of the first vaporization tube.

[0013] Optionally, the diameter of the first vaporization tube is larger than the diameter of the second vaporization tube.

[0014] Optionally, the connector includes an input pipe, an output pipe, and a buffer pipe connecting the input pipe and the output pipe, wherein the input pipe is connected to the outlet end of the first vaporization pipe, and the output pipe is connected to the inlet end of the second vaporization pipe.

[0015] Optionally, the connector includes a U-shaped elbow.

[0016] Optionally, it also includes multiple heat dissipation fins, which are fixedly disposed on the outer wall surface of the second vaporization tube.

[0017] Optionally, the fins are arranged side by side along the length of the second gasification tube.

[0018] Optionally, the medium inlet is located on the bottom plate, and the medium outlet is located on the top plate.

[0019] Optionally, it also includes:

[0020] A medium inlet pipeline is connected to the medium inlet;

[0021] A medium outlet pipeline is connected to the medium outlet.

[0022] An inlet pump, installed on the medium inlet pipeline, is used to pump the fluid medium into the chamber;

[0023] An outlet pump, installed on the medium outlet pipeline, is used to pump the fluid medium out of the chamber.

[0024] This application also provides a liquid nitrogen vaporization cooling energy recovery system, including:

[0025] A liquid nitrogen vaporization device, comprising the liquid nitrogen vaporization device according to any one of claims 1 to 9;

[0026] A liquid nitrogen supply device is connected to the liquid nitrogen inlet of the liquid nitrogen vaporization device and is used to supply liquid nitrogen to be vaporized.

[0027] A medium supply module is connected to the medium inlet of the liquid nitrogen vaporization device and is used to input the fluid medium into the chamber of the liquid nitrogen vaporization device;

[0028] The cold energy recovery module is connected to the medium outlet of the liquid nitrogen vaporization device and is used to receive the low-temperature medium that flows out after absorbing cold energy in the heat exchange chamber, and use the cold energy of the low-temperature medium to cool the target equipment.

[0029] As described above, the liquid nitrogen vaporization device, its manufacturing method, and the display device provided by the present invention have at least the following beneficial technical effects:

[0030] The liquid nitrogen vaporization device of this invention forms a two-stage series heating system by setting up a first vaporization tube 2 and a second vaporization tube 3. The first vaporization tube 2 extends the residence time to complete the initial vaporization; the second vaporization tube 3 narrows its diameter to increase the flow velocity and enhance turbulence, so that the residual liquid droplets are completely vaporized and heated. The low-temperature nitrogen gas (approximately -40℃ to -10℃) vaporized by the first vaporization tube 2 flows inside the second vaporization tube 3, and its temperature is much higher than -196℃. When this relatively high-temperature nitrogen gas flows through the second vaporization tube 3, which is close to the outer wall of the first vaporization tube 2, heat is transferred to the outer surface of the first vaporization tube 2 through the tube wall, thereby actively suppressing frost formation. At the same time, heat dissipation fins 31 are set on the outer wall of the second vaporization tube 3, and the circulating liquid medium is controlled above 0℃ to flush the heat dissipation fins 31, eliminating icing at the source and avoiding the drawbacks of frequent shutdowns for defrosting or reliance on electric heating in traditional ambient temperature vaporizers.

[0031] In addition, the liquid nitrogen vaporization cold energy recovery system provided in this application has a reduced temperature after the medium absorbs the cold energy released by the vaporization of liquid nitrogen in the vaporization device, and is directly transported to cooling equipment such as air conditioning surface coolers and process cooling equipment to realize the recovery and utilization of cold energy, avoiding the waste of cold energy directly lost by traditional ambient temperature vaporizers. Attached Figure Description

[0032] Figure 1 The diagram shown is a structural schematic of the liquid nitrogen vaporization device provided in Example 1.

[0033] Figure 2 Displayed as Figure 1 The diagram shows a cross-sectional view of the liquid nitrogen vaporization device.

[0034] Figure 3 Displayed as Figure 1 The diagram shows the structure of the connector.

[0035] Figure 4 Displayed as Figure 3 A structural schematic diagram of the cross-sectional view of the connector.

[0036] Figure 5 Not displayed Figure 1 The diagram shows the structure of the second vaporization tube.

[0037] Figure 6 The diagram shown is a structural schematic of the liquid nitrogen vaporization cooling energy recovery system provided in Example 2.

[0038] Reference numerals: 1. Outer shell; 10. Chamber; 11. Side wall; 12. Top plate; 13. Bottom plate; 14. Liquid nitrogen inlet; 15. Nitrogen outlet; 16. Medium inlet; 17. Medium outlet; 18. Insulation layer; 2. First vaporization pipe; 3. Second vaporization pipe; 31. Heat dissipation fins; 4. Connector; 41. Input pipe; 411. First fixing part; 42. Output pipe; 421. Second fixing part; 43. Buffer pipe; 431. Buffer section; 432. Transition section; 51. Medium inlet pipe; 511. Inlet pump; 52. Medium outlet pipe; 521. Outlet pump; 6. Support;

[0039] 100. Liquid nitrogen vaporization device; 200. Liquid nitrogen supply device; 300. Medium supply module; 400. Cold energy recovery module. Detailed Implementation

[0040] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0041] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Although the illustrations only show components related to the present invention and are not drawn according to the actual number, shape and size of the components, the shape, quantity, positional relationship and proportion of each component can be arbitrarily changed under the premise of realizing the technical solution of this invention, and the layout of the components may also be more complex.

[0042] Example 1

[0043] This embodiment provides a liquid nitrogen vaporization device, such as... Figure 1 and Figure 2 As shown, the liquid nitrogen vaporization device of this embodiment includes: a shell 1, with a sealed heat exchange chamber formed inside; a first vaporization pipe 2, a second vaporization pipe 3, and a connector 4 connecting the first vaporization pipe 2 and the second vaporization pipe 3.

[0044] Generally, the outer shell 1 has a cylindrical, cuboid, or elliptical cylindrical shape. In this embodiment, the outer shell 1 is cylindrical, and its dimensions are determined based on the heat exchange power, spiral tube parameters, and medium flow rate. Generally, the inner diameter of the outer shell 1 is between 300mm and 600mm, preferably 400mm; the height of the outer shell 1 is between 800mm and 2000mm, preferably 1200mm. Specifically, the outer shell 1 includes a side wall 11 and a top plate 12 and a bottom plate 13 disposed opposite to each other. The side wall 11, the top plate 12, and the bottom plate 13 form a sealed heat exchange chamber 10. The outer shell 1 is provided with a liquid nitrogen inlet 14 and a nitrogen outlet 15, as well as a medium inlet 16 and a medium outlet 17. Generally, the positions of the liquid nitrogen inlet 14 and the nitrogen outlet 15 are adjusted according to the pipeline layout inside the cavity of the outer shell 1. In this embodiment, liquid nitrogen is conveyed from the bottom to the top of the cavity through the first vaporization pipe 2, and then conveyed to the bottom of the cavity of the outer shell 1 through the second vaporization pipe 3. Therefore, the liquid nitrogen inlet 14 and the nitrogen outlet 15 are both located on the side wall of the outer shell 1, and both are located at the lower part of the side wall of the outer shell 1, close to the bottom plate 13. This design facilitates the entry of liquid nitrogen into the first vaporization pipe from the bottom and its smooth flow under the assistance of gravity, while also facilitating the exit of the vaporized nitrogen from the bottom.

[0045] The outer casing 1 is also provided with a medium inlet 16 and a medium outlet 17. Generally, the medium inlet 16 and the medium outlet 17 can be located on the side wall, top plate, or bottom plate of the outer casing 1 according to the flow direction of the fluid medium. In this embodiment, in order to ensure that the fluid medium can fully flush the entire heat exchange unit, the medium inlet 16 is located on the top plate 12 of the outer casing 1, and the medium outlet 17 is located on the bottom plate 13 of the outer casing 1, so as to form a medium flow path from top to bottom. Optionally, the medium inlet 16 is located on the side wall 11, near the top plate 12, and the medium outlet 17 is located on the side wall 11, near the bottom plate 13, and the medium inlet 16 and the medium outlet 17 form a transverse flush, increasing the contact area between the medium and the vaporization pipe.

[0046] Generally, the outer shell 1 is made of a metal material, such as carbon steel, stainless steel, or aluminum alloy, with a wall thickness of 3-5 mm, which can be determined by strength calculation based on the design pressure of the heat exchange chamber 10. Specifically, an insulation layer 18 is provided on the side wall 11 of the outer shell 1 to reduce heat loss. Specifically, the insulation layer 18 covers the entire side wall 11, top plate 12, and bottom plate 13 of the outer shell 1, leaving only the pipe interfaces and maintenance ports exposed. Generally, the insulation layer 18 includes rubber-plastic sponge, polyurethane foam, or glass wool, and the thickness of the insulation layer 18 is between 20-50 mm. Optionally, an aluminum sheet or galvanized iron sheet is provided on the outside of the insulation layer 18 as a protective layer.

[0047] The vaporization tube is located inside the cavity of the outer shell 1, and includes a first vaporization tube 2 and a second vaporization tube 3. Specifically, the first vaporization tube 2 is arranged in a spiral shape, and its inlet end is connected to the liquid nitrogen inlet 14; the second vaporization tube 3 is located inside the heat exchange chamber 10, and its spiral is wound around the outer wall of the first vaporization tube 2, and its outlet end is connected to the nitrogen outlet 15.

[0048] Specifically, such as Figure 1 and Figure 2 The first vaporization tube 2 is located inside the heat exchange chamber 10 and is arranged in a spiral shape. Specifically, the first vaporization tube 2 is arranged coaxially on the central axis of the outer shell 1 in the form of a cylindrical helix. The diameter and number of spiral coils of the first vaporization tube 2 are adjusted according to the size of the outer shell 1. Generally, the diameter of the first vaporization tube 2 is between 25mm and 35mm, the diameter of the cylindrical helix of the first vaporization tube 2 is between 200mm and 250mm, and the number of spiral coils is 3 to 8.

[0049] The second vaporization tube 3 is located inside the heat exchange chamber 10, and is spirally wound around the outer wall of the first vaporization tube 2. The diameter of the second vaporization tube 3 is smaller than that of the first vaporization tube 2, and generally, the diameter of the second vaporization tube 3 is between 8 mm and 12 mm. The second vaporization tube 3 is wound along the outer wall of the spiral section of the first vaporization tube 2 in a tight contact manner with equal pitch. The winding pitch is between 10 and 20 mm, and the number of winding turns is determined according to the length of the first vaporization tube 2, generally between 40 and 80 turns.

[0050] Specifically, the second vaporization tube 3 is wound in the opposite direction to the spiral direction of the first vaporization tube 2, so as to generate counter-current crossflow between the tubes and enhance heat transfer. Specifically, when the first vaporization tube 2 extends spirally in a first direction, the second vaporization tube 3 is tightly wound around the outer wall of the first vaporization tube 2 in a second direction, so that the winding path of the second vaporization tube 3 intersects the spiral line of the first vaporization tube 2. Figure 2 As shown, the first vaporization tube 2 spirals from the lower right to the upper right, which is a left-hand spiral, and the second vaporization tube 3 spirals from the lower left to the upper right of the first vaporization tube 2, which is a right-hand spiral.

[0051] Connector 4 connects the outlet end of the first vaporization pipe 2 to the inlet end of the second vaporization pipe 3; for example Figure 3 The diagram shown is a structural schematic of the connector provided in this embodiment. Figure 4 Displayed as Figure 3 The diagram shows a cross-sectional view of the connector; generally, connector 4 includes an input pipe 41, an output pipe 42, and an intermediate buffer pipe 43; the buffer pipe 43 connects the input pipe 41 and the output pipe 42, and is used to achieve a smooth transition of fluid from the input pipe 41 to the output pipe 42 and to adapt the pipe diameter. The input pipe 41 is connected to the outlet end of the first vaporization pipe 2, and the output pipe 42 is connected to the inlet end of the second vaporization pipe 3. In this embodiment, as shown... Figure 4 As shown, connector 4 includes a U-shaped elbow, which has an overall U-shaped or semi-circular structure, reducing the pipe diameter from large to small or vice versa. Optionally, the angle of the U-shaped elbow can be 90° to 180°, such as 135°. In this embodiment, connector 4 uses a 180° rotating U-shaped elbow, which reduces the pipe diameter and reverses the flow direction by 180°, so that the low-temperature nitrogen flowing out of the first vaporization pipe 2 enters the second vaporization pipe 3, which is spirally wound in the opposite direction, after a 180° turn.

[0052] Specifically, such as Figure 3 and Figure 4 As shown, the inlet end of the input pipe 41 is provided with a first fixing part 411, which fixes the input pipe 41 to the first vaporization pipe 2; the outlet end of the output pipe 42 is provided with a second fixing part 421, which fixes the output pipe 42 to the second vaporization pipe 3. Optionally, the buffer pipe 43 includes a buffer section 431 and a transition section 432; the buffer section 431 is located inside the intermediate buffer pipe 43, and is curved in an arc shape with a bending radius R of 30mm to 60mm. The inner wall of the buffer section 431 is smooth, without sharp corners or abrupt changes, to ensure minimal pressure loss when the fluid changes direction. The cross-sectional area of ​​the buffer section 431 can be constant or gradually changing. The transition section 432 is located between the inlet end of the input pipe 41 and the buffer section 431, or between the buffer section 431 and the outlet end of the output pipe 42. The inner diameter of the transition section 432 gradually decreases, forming a tapered flow channel.

[0053] Optionally, the connector 4 is made of the same or compatible metal material as the first vaporization tube 2 and the second vaporization tube 3, preferably stainless steel, to adapt to cryogenic liquid nitrogen conditions and ensure weld compatibility. Specifically, the connector 4 is manufactured using a one-piece molding process.

[0054] Optionally, a first control valve 44 is installed between the output pipeline 42 and the inlet end of the second vaporization pipe 3 to regulate the flow rate of nitrogen entering the second vaporization pipe 3. When the liquid nitrogen consumption is small, the first control valve 44 can be partially closed to prolong the residence time of nitrogen in the second vaporization pipe 3 and improve the heat exchange effect; when the liquid nitrogen consumption is large, the first control valve 44 can be fully opened to meet the large flow rate requirement. Generally, the first control valve 44 includes a ball valve or a regulating valve.

[0055] Optionally, a second outlet 45 is provided on the side wall of the buffer pipe 43, away from the first vaporization pipe 2 and the second vaporization pipe 3. A second control valve 46 is installed on the second outlet 45. Opening the second control valve 46 and closing the first control valve 44 allows the nitrogen gas from the outlet of the first vaporization pipe 2 to be discharged directly through the second outlet 45 without entering the second vaporization pipe 3. This is suitable for operating conditions where the liquid nitrogen load is extremely low and the temperature requirements are met by the first-stage heat exchange.

[0056] Specifically, such as Figure 5 As shown, the liquid nitrogen vaporization device in this embodiment also includes multiple heat dissipation fins 31, which are fixedly disposed on the outer wall surface of the second vaporization tube 3. Generally, the heat dissipation fins 31 include thin metal sheets, made of materials with high thermal conductivity such as aluminum or copper alloys; for example... Figure 4 As shown, the heat dissipation fins 31 are rectangular sheet structures. The root of the heat dissipation fins 31 is fixedly connected to the outer wall of the second vaporization tube 3. The fin body extends radially along the second vaporization tube 3. Multiple heat dissipation fins 31 are arranged at intervals along the length of the second vaporization tube 3. An airflow channel or liquid flow channel is formed between adjacent heat dissipation fins 31 for the fluid medium to flow through and exchange heat with the nitrogen gas inside the second vaporization tube 3.

[0057] Generally, the height of the heat dissipation fins 31 is between 3mm and 10mm, preferably 5mm; the spacing between adjacent heat dissipation fins 31 is between 3mm and 10mm, preferably 5mm; the length of the heat dissipation fins 31 is adjusted according to the size of the second vaporization tube 3.

[0058] Specifically, the liquid nitrogen vaporization device also includes: a medium inlet pipe 51 and a medium outlet pipe 52; the medium inlet pipe 51 is connected to the medium inlet 16; the medium outlet pipe 52 is connected to the medium outlet 17; an inlet pump 511 is installed on the medium inlet pipe 51 for pumping the fluid medium into the chamber 10; and an outlet pump 521 is installed on the medium outlet pipe 52 for pumping the fluid medium out of the heat exchange chamber 10.

[0059] Generally, the inlet pump 511 and outlet pump 521 are centrifugal water pumps. The inlet pump 511 and outlet pump 521 can operate simultaneously, or one can be selected to operate independently depending on the operating conditions. When operating simultaneously, the two pumps form a series boosting effect, which can overcome a large total pipeline resistance. Optionally, only the outlet pump 521 can be turned on while the inlet pump 511 is turned off. The suction effect of the outlet pump 521 creates a slight negative pressure within the heat exchange chamber 10, which helps to remove air bubbles entrained in the medium and improves heat exchange efficiency. Optionally, a differential pressure sensor or flow sensor can be installed between the inlet pump 511 and outlet pump 521, and a controller can be provided. The controller automatically adjusts the speed of the two pumps based on the detection signal, ensuring the system always operates in an optimal matching state.

[0060] Specifically, in this embodiment, the fluid medium includes: water, a water-ethylene glycol mixture, heat transfer oil, air, or other gaseous media. On one hand, the fluid medium acts as a heat source, providing heat to the cryogenic liquid nitrogen / nitrogen gas in the first vaporization pipe 2 and the second vaporization pipe 3, promoting the vaporization of liquid nitrogen and increasing the temperature of the nitrogen gas; on the other hand, it absorbs cold energy and becomes a cryogenic medium, which is then transported to the refrigeration equipment through the medium outlet 17 and the outlet pump 521, thus achieving cold energy recovery.

[0061] Specifically, two supports 6 are provided inside the chamber 10. The supports 6 are arranged along the height direction of the outer shell 1, extending from the bottom plate 13 to the top plate 12, and running through the entire heat exchange chamber 10. Specifically, as shown... Figure 1 He Rang Figure 2 As shown, two supports 6 are located near both ends of the spiral section of the first vaporization tube 2, respectively, and are used to fix the first vaporization tube 2 and the second vaporization tube 3 wound around it.

[0062] The working process of the liquid nitrogen vaporization device provided in this application is briefly described as follows:

[0063] Liquid nitrogen (approximately -196°C) enters the inlet end 21 of the first vaporization pipe 2 through the liquid nitrogen inlet 14 and flows upward along the spiral-shaped first vaporization pipe 2. During the flow, the liquid nitrogen absorbs heat from the fluid medium in the heat exchange chamber 10, and its temperature gradually rises, partially vaporizing to form a gas-liquid two-phase mixture (temperature approximately -40°C). After reaching the outlet end 22 of the first vaporization pipe 2, the mixture enters the connector 4. The connector 4 directs the mixture into the second vaporization pipe 3. In the second vaporization pipe 3, the mixture flows spirally in the opposite direction to the flow direction in the first vaporization pipe 2, further absorbing heat transferred by the fins and pipe walls, causing the remaining liquid components to completely vaporize. The nitrogen temperature continues to rise to near the medium temperature (e.g., 10~20°C), and finally exits from the nitrogen outlet 15 for downstream use.

[0064] The liquid nitrogen vaporization device provided in this embodiment forms a two-stage series heating system by setting up a first vaporization tube 2 and a second vaporization tube 3. The first vaporization tube 2 extends the residence time to complete the initial vaporization; the second vaporization tube 3 reduces the diameter to increase the flow velocity and enhance turbulence, so that the residual liquid droplets are completely vaporized and heated. The low-temperature nitrogen gas (approximately -40℃ to -10℃) vaporized by the first vaporization tube 2 flows in the second vaporization tube 3, and its temperature is much higher than -196℃. When this relatively high-temperature nitrogen gas flows through the second vaporization tube 3, which is close to the outer wall of the first vaporization tube 2, heat is transferred to the outer surface of the first vaporization tube 2 through the tube wall, thereby actively suppressing frost formation. At the same time, heat dissipation fins 31 are set on the outer wall of the second vaporization tube 3, and the circulating liquid medium is controlled above 0℃ to flush the heat dissipation fins 31, eliminating icing at the source and avoiding the drawbacks of frequent shutdowns for defrosting or reliance on electric heating in traditional ambient temperature vaporizers.

[0065] Example 2

[0066] This embodiment provides a liquid nitrogen vaporization cooling energy recovery system, such as Figure 6 The diagram shown is a schematic representation of the liquid nitrogen vaporization cold energy recovery system provided in this embodiment. The liquid nitrogen vaporization cold energy recovery system includes: a liquid nitrogen vaporization device 100, a liquid nitrogen supply device 200, a medium supply module 300, and a cold energy recovery module 400.

[0067] Specifically, the liquid nitrogen vaporization device 100 includes the liquid nitrogen vaporization device described in Embodiment 1; the liquid nitrogen vaporization device 100 is provided with a liquid nitrogen inlet 14, a nitrogen outlet 15, a medium inlet 16, and a medium outlet 17. Its specific structure, connection relationship, and working process have been described in detail in Embodiment 1, and will not be repeated here.

[0068] Specifically, the liquid nitrogen supply device 200 is connected to the liquid nitrogen inlet of the liquid nitrogen vaporization device and is used to supply liquid nitrogen to be vaporized. The liquid nitrogen supply device 200 includes a liquid nitrogen storage tank, a liquid nitrogen tank truck, or a liquid nitrogen pipeline system, etc., and stores cryogenic liquid nitrogen inside. The outlet end of the liquid nitrogen supply device 200 may be equipped with a shut-off valve and a pressure regulating valve to control the flow rate and pressure of liquid nitrogen entering the liquid nitrogen vaporization device 100.

[0069] Specifically, the medium supply module 300 is connected to the medium inlet of the liquid nitrogen vaporization device and is used to input the fluid medium into the chamber of the liquid nitrogen vaporization device; generally, the fluid medium includes a liquid medium or a gaseous medium. The liquid medium can be selected from water, a water-ethylene glycol mixture, heat transfer oil, or other liquids with fluidity and thermal conductivity; the gaseous medium can be selected from air, nitrogen, or other inert gases.

[0070] Specifically, the cold energy recovery module 400 is connected to the medium outlet of the liquid nitrogen vaporization device, and is used to receive the low-temperature medium flowing out after absorbing cold energy in the heat exchange chamber, and to use the cold energy of the low-temperature medium to cool the target equipment. In this embodiment, the cold energy recovery module 400 includes cooling equipment, which includes the surface cooler of an air conditioning system, a process cooling device, an evaporator of a cold storage, or any heat exchange equipment that requires cold energy. The inlet of the cooling equipment is directly connected to the medium outlet 17 through an insulated pipe.

[0071] The liquid nitrogen vaporization cooling energy recovery system provided in this embodiment reduces the temperature of the medium after absorbing the cooling energy released by liquid nitrogen vaporization in the vaporization device. The medium is then directly transported to cooling equipment such as air conditioning surface coolers and process cooling equipment, realizing the recovery and utilization of cooling energy and avoiding the waste of cooling energy directly lost by traditional ambient temperature vaporizers.

[0072] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A liquid nitrogen vaporization device, characterized in that, include: The outer casing includes side walls and a top plate and a bottom plate disposed opposite to each other, the side walls forming a sealed chamber with the top plate and the bottom plate; the outer casing is provided with a liquid nitrogen inlet and a nitrogen outlet, as well as a medium inlet and a medium outlet; The first vaporization tube is located in the chamber. The first vaporization tube is arranged in a spiral shape, and the inlet end of the first vaporization tube is connected to the liquid nitrogen inlet. The second vaporization tube is located in the chamber. The second vaporization tube is spirally wound around the outer wall of the first vaporization tube. The outlet end of the second vaporization tube is connected to the nitrogen outlet. A connector connects the outlet end of the first vaporization pipe to the inlet end of the second vaporization pipe.

2. The liquid nitrogen vaporization device according to claim 1, characterized in that, The first vaporization tube is arranged coaxially on the central axis of the shell in the form of a cylindrical helix; the second vaporization tube is wound in the opposite direction to the helix direction of the first vaporization tube.

3. The liquid nitrogen vaporization device according to claim 1, characterized in that, The diameter of the first vaporization tube is larger than the diameter of the second vaporization tube.

4. The liquid nitrogen vaporization device according to claim 3, characterized in that, The connector includes an input pipe, an output pipe, and a buffer pipe connecting the input pipe and the output pipe. The input pipe is connected to the outlet end of the first vaporization pipe, and the output pipe is connected to the inlet end of the second vaporization pipe.

5. The liquid nitrogen vaporization device according to claim 4, characterized in that, The connector includes a U-shaped elbow.

6. The liquid nitrogen vaporization device according to claim 1, characterized in that, It also includes multiple heat dissipation fins, which are fixedly disposed on the outer wall surface of the second vaporization tube.

7. The liquid nitrogen vaporization device according to claim 6, characterized in that, The fins are arranged side by side along the length of the second gasification tube.

8. The liquid nitrogen vaporization device according to claim 1, characterized in that, The medium inlet is located on the bottom plate, and the medium outlet is located on the top plate.

9. The liquid nitrogen vaporization device according to claim 1, characterized in that, Also includes: A medium inlet pipeline is connected to the medium inlet; A medium outlet pipeline is connected to the medium outlet. An inlet pump, installed on the medium inlet pipeline, is used to pump the fluid medium into the chamber; An outlet pump, installed on the medium outlet pipeline, is used to pump the fluid medium out of the chamber.

10. A liquid nitrogen vaporization cooling energy recovery system, characterized in that, include: A liquid nitrogen vaporization device, comprising the liquid nitrogen vaporization device according to any one of claims 1 to 9; A liquid nitrogen supply device is connected to the liquid nitrogen inlet of the liquid nitrogen vaporization device and is used to supply liquid nitrogen to be vaporized. A medium supply module is connected to the medium inlet of the liquid nitrogen vaporization device and is used to input the fluid medium into the chamber of the liquid nitrogen vaporization device; The cold energy recovery module is connected to the medium outlet of the liquid nitrogen vaporization device. It is used to receive the low-temperature medium that flows out after absorbing cold energy in the chamber, and to use the cold energy of the low-temperature medium to cool the target equipment.

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