Nitrogen charging system and cold box

Abstract

The utility model discloses a nitrogen charging system, which is used for charging nitrogen for a cold box body and comprises a nitrogen blowing pipeline, a nitrogen discharging pipeline and a nitrogen discharging pipeline, one end of the connecting pipeline communicates with the nitrogen blowing pipeline, and the other end of the connecting pipeline communicates with an external nitrogen supply pipe; the control assembly comprises a pressure regulating valve, a first pressure gauge and a flow meter; the pressure regulating valve, the first pressure gauge and the flow meter are sequentially arranged on the connecting pipeline at intervals in the flowing direction of nitrogen in the connecting pipeline. The nitrogen charging system disclosed by the utility model can be used for completely and efficiently charging nitrogen into the cold box body. The utility model further provides the cold box.

Description

Technical Field

[0001] This utility model relates to the field of industrial gases, and in particular to a nitrogen filling system and a cold box. Background Technology

[0002] Cold boxes are widely used in various industrial gas projects and are a hallmark of large-scale air separation units and liquefied natural gas (LNG) plants. Cold boxes are cryogenic operating equipment. During operation, the containers and pipelines within a cold box contain a large amount of cryogenic media. To maintain the cold, perlite is placed inside the cold box. Air is trapped between the perlite particles. This air contains moisture, and the extremely low temperature causes condensation, resulting in significant frost formation on the equipment surface. Therefore, in the initial stages of operation, the air inside the perlite of the cold box needs to be replaced with nitrogen to reduce energy loss and optimize the cold box's performance. Utility Model Content

[0003] The purpose of this invention is to solve the problem of how to completely and efficiently fill a cold box with nitrogen. This invention provides a nitrogen filling system and a cold box that can completely and efficiently fill a cold box with nitrogen.

[0004] To solve the above-mentioned technical problems, the present invention discloses a nitrogen filling system for filling a cold box body with nitrogen. The nitrogen filling system includes: a nitrogen blowing pipe, including an outlet; a connecting pipe, one end of which is connected to the nitrogen blowing pipe and the other end of which is used to connect to an external nitrogen supply pipe; and a control component, including a pressure regulating valve, a first pressure gauge, and a flow meter. Along the flow direction of nitrogen in the connecting pipe, the pressure regulating valve, the first pressure gauge, and the flow meter are sequentially and spaced apart on the connecting pipe.

[0005] Using the above technical solution, an external nitrogen supply pipe supplies nitrogen to the nitrogen purging pipe via a connecting pipe. The nitrogen in the purging pipe is discharged from the outlet to purge the perlite inside the cold box body. This displaces the air inside the perlite with nitrogen, keeping it dry and improving the cold box performance. During the flow of nitrogen from the connecting pipe to the nitrogen purging pipe, a pressure regulating valve is located near the inlet of the connecting pipe to adjust the nitrogen pressure entering the pipe. Since the nitrogen pressure required for purging is relatively low, it can be reduced using the pressure regulating valve. The first pressure gauge after the pressure regulating valve is used to check if the purging pressure meets the requirements. If not, the pressure can be readjusted using the pressure regulating valve. A flow meter after the first pressure gauge monitors the gas flow rate, ensuring sufficient flow while preventing waste of purging gas.

[0006] In summary, this application utilizes a nitrogen purging pipeline to purge perlite through its outlet. Furthermore, the control components located on the connecting pipeline provide precise control over the gas purging pressure and the total gas replacement volume, thereby achieving complete and efficient air replacement.

[0007] According to another specific embodiment of the present invention, it further includes: a support plate, fixedly connected to the lower part of the nitrogen blowing pipe, the support plate being used to connect with the panel of the cold box body; and an air inlet pipe, connecting the connecting pipe and the nitrogen blowing pipe.

[0008] According to another specific embodiment of the present invention, the nitrogen blowing pipe is wrapped with a filter element.

[0009] According to another specific embodiment of the present invention, the filter element is fine gauze.

[0010] Using the above technical solution, the perlite inside the cold box body is a fine powder, which may cause blockage and flow into the nitrogen blowing pipe. Therefore, fine gauze is used to wrap the nitrogen blowing pipe to reduce the contact between the air outlet on the nitrogen blowing pipe and the perlite.

[0011] According to another specific embodiment of the present invention, the nitrogen blowing pipeline includes: a plurality of straight pipes, each of the plurality of straight pipes having a plurality of sets of air outlets spaced apart along its axial direction, each set of air outlets including two air outlets spaced apart along the circumference of the straight pipe; and a plurality of elbows, each of the two ends of the straight pipe being connected to two elbows respectively.

[0012] According to another specific embodiment of the present invention, any two adjacent sets of air outlets in the plurality of sets of air outlets are spaced 80mm to 120mm apart in the axial direction of the straight pipe.

[0013] According to another specific embodiment of the present invention, the two air outlets in each group are arranged at intervals in the circumferential direction of the straight pipe, and the angle between the radial line of any one of the two air outlets and the radial line of the lowest point of the straight pipe is 30° to 60°.

[0014] According to another specific embodiment of the present invention, the control component further includes a second pressure gauge, which is used to detect the pressure inside the cold box body.

[0015] Using the above technical solution, the cold box body is a sealed enclosure, and continuous ventilation creates internal pressure. If the internal pressure becomes too high, the gas needs to be promptly vented from the cold box body; otherwise, it will pose a safety hazard. A second pressure gauge detects the internal pressure of the cold box body, and its reading can be used to determine if there are any abnormalities in the nitrogen gas levels inside the cold box body.

[0016] The present invention also discloses a cold box based on a nitrogen filling system according to any of the above embodiments, comprising: a cold box body including a panel; and the nitrogen filling system, wherein the nitrogen blowing pipe is fixed to the panel of the cold box body.

[0017] According to another specific embodiment of the present invention, the cold box body further includes a support frame, the panel includes an upper panel disposed on the top of the support frame and a lower panel disposed on the bottom of the support frame, and the nitrogen blowing pipe is fixed on both the upper panel and the lower panel, and the nitrogen blowing pipe on the upper panel and the nitrogen blowing pipe on the lower panel are connected.

[0018] Using the above technical solution, when the internal gas volume of the cold box body is >300m³ 3 Setting up only one nitrogen purging pipe cannot meet the total gas replacement volume. Nitrogen purging pipes can be set on both the upper and lower plates at the same time. The nitrogen purging pipes on the upper and lower plates are connected and nitrogen is supplied through an external nitrogen supply pipe, thereby ensuring the purging effect while simplifying the structure and reducing the space occupied. Attached Figure Description

[0019] Figure 1 This invention illustrates a three-dimensional representation of the cold box according to an embodiment of the present invention. Figure 1 ;

[0020] Figure 2 A partial perspective view of a cold box according to an embodiment of the present invention is shown, wherein the side panel and the fixed box are not shown;

[0021] Figure 3 A schematic diagram showing the distribution of air outlets on a straight pipe according to an embodiment of the present invention is shown;

[0022] Figure 4 This invention illustrates a three-dimensional representation of the cold box according to an embodiment of the present invention. Figure 2 The side panel is not shown, but nitrogen blowing pipes are provided on both the top and bottom panels.

[0023] Figure 5 A perspective view of the connecting pipes and control components according to an embodiment of the present invention is shown;

[0024] Figure 6 This is a schematic cross-sectional view of the air outlets distributed on the straight pipe according to an embodiment of the present invention. Detailed Implementation

[0025] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Although the description of this utility model will be presented in conjunction with preferred embodiments, this does not mean that the features of this utility model are limited to this embodiment. On the contrary, the purpose of describing the utility model in conjunction with the embodiments is to cover other options or modifications that may be derived based on the claims of this utility model. To provide a deep understanding of this utility model, many specific details will be included in the following description. This utility model may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this utility model, some specific details will be omitted in the description. It should be noted that, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0026] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.

[0028] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0029] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0031] refer to Figure 1 and Figure 2This application provides a cold box 100, including a cold box body 200 and a nitrogen filling system 300. For cold preservation, the cold box body 200 is filled with perlite. The nitrogen filling system 300 is used to fill the cold box body 200 with nitrogen, so as to replace the air inside the perlite with nitrogen, keep the perlite dry, and improve the performance of the cold box.

[0032] Understandably, the interior of the 200-ton cold box body is... Figure 1 The relatively enclosed space shown is surrounded by a support frame 210, multiple side panels 202, a lower panel 201, and an upper panel 203, wherein the lower panel 201 is located at the bottom of the support frame 210 and the upper panel 203 is located at the top of the support frame 210. Figure 2 To facilitate the illustration of the nitrogen filling system 300, only the support frame 210 of the cold box body 200 is shown, while multiple side panels 202 and the top panel 203 are omitted, and the bottom panel 201 is retained.

[0033] Specifically, such as Figure 2 and Figure 3 As shown, the nitrogen filling system 300 includes a nitrogen blowing pipe 400, a connecting pipe 500, and a control component 600. The nitrogen blowing pipe 400 is fixed to the lower panel 201 inside the cold box body 200. The nitrogen blowing pipe 400 includes an outlet 401. One end of the connecting pipe 500 is connected to the nitrogen blowing pipe 400, and the other end is used to connect to an external nitrogen supply pipe (not shown in the figure). That is, the external nitrogen supply pipe supplies nitrogen to the nitrogen blowing pipe 400 through the connecting pipe 500, and the nitrogen in the nitrogen blowing pipe 400 can be discharged from the outlet 401 to purge the perlite inside the cold box body 200.

[0034] In this embodiment, the nitrogen blowing pipe 400 is fixed to the lower panel 201 inside the cold box body 200. However, those skilled in the art will understand that in other embodiments, the nitrogen blowing pipe 400 may also be fixed to the upper panel 203 inside the cold box body 200. Further, as... Figure 4 As shown, when the internal gas volume of the cold box body 200 is >300m³ 3 Setting up only one nitrogen purging pipe 400 cannot meet the total gas replacement volume. Nitrogen purging pipes 400 can be set on the upper plate 203 and the lower plate 201 at the same time. The nitrogen purging pipes 400 on the upper plate 203 and the lower plate 201 are connected and nitrogen is supplied through an external nitrogen supply pipe, thereby ensuring the purging effect while simplifying the structure and reducing the space occupied.

[0035] For example, such as Figure 2 and Figure 5As shown, the connecting pipe 500 includes an inlet end 501 and an outlet end 502. The inlet end 501 is used to connect to an external nitrogen supply pipe, and the outlet end 502 is connected to a nitrogen blowing pipe 400. In this embodiment, the inlet end 501 is provided with a flange 503 to connect to the external nitrogen supply pipe, thereby achieving a standardized connection, ensuring sealing performance, and facilitating disassembly and maintenance.

[0036] The aforementioned control component 600 includes a pressure regulating valve 601, a first pressure gauge 602, and a flow meter 603. Along the flow direction of nitrogen gas within the connecting pipe 500, i.e., from the inlet end 501 to the outlet end 502, the pressure regulating valve 601, the first pressure gauge 602, and the flow meter 603 are sequentially spaced along the connecting pipe 500. The pressure regulating valve 601 is located near the inlet end 501 of the connecting pipe 500 to regulate the nitrogen pressure. In this embodiment, the nitrogen pressure required during nitrogen purging is relatively low, and the pressure can be reduced by the pressure regulating valve 601.

[0037] Along the flow direction of nitrogen gas within the connecting pipe 500, the first pressure gauge 602 is located downstream of the pressure regulating valve 601. That is, the nitrogen gas in the connecting pipe 500 flows from the pressure regulating valve 601 towards the location of the first pressure gauge 602. In other words, the first pressure gauge 602 is closer to the outlet end 502 of the connecting pipe 500 than the pressure regulating valve 601. The first pressure gauge 602 is used to observe whether the purging pressure value meets the requirements. If it does not meet the requirements, it can be readjusted through the pressure regulating valve 601. In this embodiment, to provide sufficient installation space for the first pressure gauge 602, the first pressure gauge 602 is connected to the connecting pipe 500 via an extension pipe 610. However, those skilled in the art will understand that in other embodiments, the first pressure gauge 602 can be directly installed on the connecting pipe 500.

[0038] Along the flow direction of nitrogen gas within the connecting pipe 500, the flow meter 603 is located downstream of the first pressure gauge 602. This means the nitrogen gas in the connecting pipe 500 flows from the first pressure gauge 602 towards the flow meter 603. In other words, the flow meter 603 is closer to the outlet end 502 of the connecting pipe 500 than the first pressure gauge 602. The nitrogen purging process is continuous throughout the day. The flow rate is obtained by dividing the total amount of purging gas by 24 hours. The amount of purging gas used is set via the flow meter 603 to ensure sufficient flow while preventing waste of purging gas.

[0039] In this embodiment, a shut-off valve 606 is provided between the inlet end 501 of the connecting pipe 500 and the pressure regulating valve 601 to cut off or open the flow of nitrogen in the connecting pipe 500. For example, when the pressure regulating valve 601 needs to be replaced, the nitrogen flowing from the inlet end 501 to the pressure regulating valve 601 can be directly shut off through the shut-off valve 606. Similarly, a shut-off valve 607 is also provided near the outlet end 502 to open or close the flow of nitrogen from the connecting pipe 500 to the nitrogen blowing pipe 400.

[0040] like Figure 1 , Figure 2 and Figure 4 As shown, the connecting pipe 500 is fixed inside a fixed box 700. A mounting hole is provided on the side panel 202 of the cold box body 200. The outer wall of the fixed box 700 is welded to the wall of the mounting hole for a sealed connection, preventing leakage of gas and perlite from inside the cold box body 200. An inlet pipe 800, connected to the nitrogen blowing pipe 400, extends into the fixed box 700 and connects to the outlet end 502 of the connecting pipe 500 inside the fixed box 700. The side of the fixed box 700 facing outwards from the cold box body 200 exposes the control component 600 for operator control.

[0041] For example, such as Figure 5 As shown, multiple angle steels 504 are fixed on the connecting pipe 500, and the angle steels 504 are welded to the inner wall of the fixed box 700.

[0042] refer to Figures 1 to 3 as well as Figure 5 Using the above technical solution, an external nitrogen supply pipe supplies nitrogen to the nitrogen purging pipe 400 via a connecting pipe 500. The nitrogen in the nitrogen purging pipe 400 is discharged from the outlet 401 to purge the perlite inside the cold box body 200. This replaces the air inside the perlite with nitrogen, keeping it dry and improving the cold box performance. During the flow of nitrogen from the connecting pipe 500 to the nitrogen purging pipe 400, a pressure regulating valve 601 is located near the inlet 501 of the connecting pipe 500 to adjust the nitrogen pressure entering the connecting pipe 500. Since the nitrogen pressure required for purging is relatively low, it can be reduced using the pressure regulating valve 601. The first pressure gauge 602, located after the pressure regulating valve 601, observes whether the purging pressure meets the requirements. If not, it can be readjusted using the pressure regulating valve 601. A flow meter 603, located after the first pressure gauge 602, detects the gas flow rate, ensuring sufficient flow while preventing waste of purging gas.

[0043] In summary, this application utilizes a nitrogen purging pipe 400 installed within the cold box body 200 to purge perlite through the outlet 401 on the nitrogen purging pipe 400. This method is simple to construct and highly operable. Furthermore, the control component 600 installed on the connecting pipe 500 provides precise control over the gas purging pressure and the total gas replacement volume, thereby achieving complete and efficient air replacement.

[0044] In some possible implementations, such as Figure 2 As shown, the nitrogen filling system 300 also includes a support plate 900 and an air inlet pipe 800. The support plate 900 is fixedly connected to the lower part of the nitrogen blowing pipe 400 and is connected to the lower panel 201 of the cold box body 200. The air inlet pipe 800 connects the connecting pipe 500 and the nitrogen blowing pipe 400.

[0045] In this embodiment, as Figure 2 , Figure 3 and Figure 5 As shown, the nitrogen blowing pipe 400 is rectangular in shape, which is adapted to the shape of the lower panel 201 inside the cold box body 200. The nitrogen blowing pipe 400 includes multiple straight pipes 402 and multiple elbows 403. Each of the multiple straight pipes 402 has multiple sets of air outlets spaced along its axial direction X at its bottom, and each set of air outlets includes two air outlets 401 spaced circumferentially along the straight pipe 402. Both ends of each straight pipe 402 are connected to two elbows 403 respectively. That is, the multiple straight pipes 402 are connected by multiple elbows 403 to form a rectangular structure, and the multiple air outlets 401 on the straight pipes 402 are also distributed in a rectangular shape, thereby realizing large-area blowing of the perlite inside the cold box body 200.

[0046] For example, the straight pipe 402, the bend 403, the air inlet pipe 800, and the support plate 900 are welded together. The bottom of the support plate 900 is then welded to the lower panel 201 of the cold box body 200.

[0047] In some possible implementations, such as Figure 2 , Figure 3 , Figure 5 and Figure 6 As shown, any two adjacent sets of air outlets 401 in the multiple sets of air outlets are spaced 80mm to 120mm apart along the axial direction X of the straight pipe 402. The two air outlets 401 in each set are spaced apart circumferentially in the straight pipe 402, and the angle α between the radial line A containing any one of the two air outlets 401 and the radial line B containing the lowest point of the straight pipe 402 is 30° to 60°. That is, the two air outlets 401 in each set are spaced apart 60° to 120° circumferentially in the straight pipe 402.

[0048] For example, the air outlet 401 is a small round hole provided on the straight pipe 402, with a diameter of 6 mm to 10 mm.

[0049] In this embodiment, any two adjacent sets of air outlets 401 are spaced 100mm apart along the axial direction X of the straight pipe 402, and the angle α between the radial line A of any one of the two air outlets 401 and the radial line B of the lowest point of the straight pipe 402 is 45°. This arrangement ensures the comprehensiveness and efficiency of the purging. However, those skilled in the art will understand that in other embodiments, the distance between any two adjacent sets of air outlets 401 along the axial direction X of the straight pipe 402 can be other values, such as 80mm, 90mm, 110mm, 120mm, etc. Similarly, the angle α between the radial line A of any one of the two air outlets 401 and the radial line B of the lowest point of the straight pipe 402 can also be other values, such as 30°, 40°, 50°, 60°, etc.

[0050] On the other hand, in this embodiment, the air outlet 401 is located in the lower half of the straight pipe 402, which can reduce the contact between the perlite and the air outlet 401.

[0051] Furthermore, such as Figure 3 As shown, the nitrogen blowing pipe 400 is wrapped with a filter element 404. In this embodiment, the filter element 404 is fine gauze. For example, the perlite inside the cold box body 200 is a fine powder, which may cause blockage and flow into the nitrogen blowing pipe 400. Therefore, the nitrogen blowing pipe 400 is wrapped with fine gauze to reduce the contact between the air outlet 401 on the nitrogen blowing pipe 400 and the perlite, thus solving the risk of blockage during the air replacement process with a simple solution.

[0052] However, those skilled in the art will understand that in other embodiments, the filter element 404 may also be other components, such as non-woven fabric, filter paper, etc.

[0053] In some possible implementations, such as Figure 2 and Figure 5 As shown, the control component 600 also includes a second pressure gauge 604 for detecting the pressure inside the cold box body 200. Exemplarily, the second pressure gauge 604 is also located inside the fixed box 700 and is connected to a detection pipe 605 that extends out of the fixed box 700 and into the cold box body 200 to measure the pressure inside the cold box body 200.

[0054] The cold box body 200 is a closed enclosure. As air continuously flows into it, pressure will accumulate inside. If the internal pressure becomes too high, the gas must be promptly vented from the cold box body 200; otherwise, it will pose a safety hazard. The second pressure gauge 604 detects the internal pressure of the cold box body 200, and its reading can be used to determine if there are any abnormalities in the nitrogen gas levels inside the cold box body 200.

[0055] In this embodiment, the first pressure gauge 602 is a large-range pressure gauge, while the second pressure gauge 604 is a small-range pressure gauge, so that the second pressure gauge 604 can more accurately measure the pressure inside the cold box body 200.

[0056] Although the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions. Those skilled in the art can make various changes in form and detail, including some simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A nitrogen filling system for filling a cold box body with nitrogen, characterized in that, The nitrogen filling system includes: Nitrogen purging pipeline, including the outlet; A connecting pipe, one end of which is connected to the nitrogen blowing pipe, and the other end of which is used to connect to an external nitrogen supply pipe; The control components include a pressure regulating valve, a first pressure gauge, and a flow meter; along the flow direction of nitrogen in the connecting pipe, the pressure regulating valve, the first pressure gauge, and the flow meter are sequentially and spaced apart on the connecting pipe.

2. The nitrogen filling system as described in claim 1, characterized in that, Also includes: A support plate is fixedly connected to the lower part of the nitrogen blowing pipe, and the support plate is used to connect to the panel of the cold box body; An air intake pipe connects the connecting pipe and the nitrogen blowing pipe.

3. The nitrogen filling system as described in claim 1, characterized in that, The nitrogen blowing pipe is wrapped with a filter element.

4. The nitrogen filling system as described in claim 3, characterized in that, The filter element is fine gauze.

5. The nitrogen filling system as described in claim 1, characterized in that, The nitrogen blowing pipeline includes: Multiple straight pipes, each of the multiple straight pipes having multiple sets of air outlets spaced apart along its axial direction, each set of air outlets including two air outlets spaced apart along the circumference of the straight pipe; Multiple elbows, with each end of the straight pipe connected to two elbows respectively.

6. The nitrogen filling system as described in claim 5, characterized in that, Any two adjacent sets of air outlets in the multiple sets of air outlets are spaced 80mm to 120mm apart along the axial direction of the straight pipe.

7. The nitrogen filling system as described in claim 6, characterized in that, The two air outlets in each group are spaced apart in the circumferential direction of the straight pipe, and the angle between the radial line of any one of the two air outlets and the radial line of the lowest point of the straight pipe is 30° to 60°.

8. The nitrogen filling system as described in claim 1, characterized in that, The control component also includes a second pressure gauge for detecting the pressure inside the cold box body.

9. A cold box, characterized in that, include: The main body of the cold box, including the control panel; The nitrogen filling system according to any one of claims 1 to 8, wherein the nitrogen blowing pipe is fixed to the panel of the cold box body.

10. The cold box as described in claim 9, characterized in that, The cold box body also includes a support frame, and the panel includes an upper panel disposed on the top of the support frame and a lower panel disposed on the bottom of the support frame. Nitrogen blowing pipes are fixed on both the upper panel and the lower panel, and the nitrogen blowing pipes on the upper panel and the lower panel are connected.

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