Modular cold shield structure for horizontal cryogenic cold box

Abstract

The utility model relates to a modularization cold screen structure for horizontal low temperature cold box, include: shell body, be provided with a plurality of stud weld rivets on its inner wall, nut, with stud weld rivet cooperation, a plurality of cold screen unit, the cold screen unit is stratiform structure, and spliced and covered in the inner wall of shell body, be provided with gap between the inner wall of shell body and the cold screen unit, tetrafluoroethylene gasket, set up between stud weld rivet with the cold screen unit, and / or set up between the inner wall of shell body and the cold screen unit, the cold screen unit is fixed through the stud weld rivet and the nut of being pressed tightly on it, adopt the modularization structure that is spliced and covered by a plurality of stratiform cold screen unit and is fixed by stud weld rivet and nut in the inner wall of shell body, successfully solved the problem that the integral cold screen cannot be installed because of the narrow internal space of large horizontal cold box, also reduced the heat loss of system, improved the heat insulation performance.

Description

Technical Field

[0001] This utility model relates to the field of low-temperature storage technology, specifically to a modular cold shield structure for horizontal low-temperature cold boxes. Background Technology

[0002] Currently, in cryogenic fields such as hydrogen and helium liquefaction, cold boxes are one of the core pieces of equipment. To reduce radiative and conductive heat transfer from the external environment to the internal cryogenic components, cold boxes typically have a cold shield structure between the outer shell and the internal components. Traditional cold shields are often made of a composite of high-reflectivity metal foil (such as aluminum foil) and low-thermal-conductivity insulation materials. The high reflectivity reduces radiative heat, and the low thermal conductivity reduces conductive heat, thereby effectively reducing overall system heat leakage and achieving energy conservation and consumption reduction.

[0003] For systems with small liquefaction or cooling capacities, vertical cold boxes are typically used. Their internal space is relatively regular, and the cold shield components can be designed as an integral structure, which is prefabricated externally and then hoisted into the cold box as a whole, making installation relatively simple.

[0004] However, with the increasing demand for liquefaction and refrigeration capacity, the application of large horizontal cold boxes is becoming increasingly widespread. Compared with vertical structures, horizontal cold boxes are characterized by their large size, complex internal containers and piping systems, and narrow operating space between the outer shell and the inner liner. Against this backdrop, the traditional integral cold shield structure has revealed significant limitations: due to its enormous size and structural rigidity, it cannot be bent or adjusted within the narrow horizontal space, making proper installation impossible. Forcibly dividing it into sections or using other alternative methods results in extremely low installation efficiency, poor sealing between components, and easy loosening, detachment, or damage during transportation and use. These defects not only affect the efficiency of installation and maintenance but also compromise the integrity and stability of the cold shield, leading to a significant decrease in its insulation performance and ultimately increasing system energy consumption.

[0005] Therefore, there is an urgent need in this field for a new type of cold shield structure that can adapt to the narrow space of a horizontal cold box, is easy to install, and can ensure long-term operational stability. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model provides a modular cold shield structure for horizontal low-temperature cold boxes, aiming to solve one or more problems existing in the background technology.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a modular cold shield structure for a horizontal low-temperature cold box, comprising: an outer shell body, on which a plurality of studs are provided on the inner wall; a nut that cooperates with the studs; a plurality of cold shield units, wherein the cold shield units are layered structures and are spliced ​​to cover the inner wall of the outer shell body; a gap is provided between the cold shield units and the inner wall of the outer shell body; a PTFE gasket is provided between the studs and the cold shield units, and / or between the inner wall of the outer shell body and the cold shield units; the cold shield units are pressed and fixed by the studs and nuts passing through them.

[0008] Furthermore, the cold screen unit includes a mirrored aluminum foil and a heat insulation layer stacked together.

[0009] Furthermore, the mirrored aluminum foil and the heat insulation layer are fixedly connected by stitching.

[0010] Furthermore, the insulation layer has multiple vent holes.

[0011] Furthermore, the edges of adjacent cold screen units overlap each other.

[0012] Furthermore, a nut is provided on the stud, and the nut is made of heat-insulating material.

[0013] Furthermore, the nut is a flange nut.

[0014] Furthermore, the cold shield unit includes rectangular or arc-shaped plates for covering the cylindrical part, and / or circular and fan-shaped units for covering the end cap.

[0015] Furthermore, the studs are arranged in an array on the inner wall of the outer casing at a spacing of 400mm to 600mm.

[0016] This utility model describes a modular cold shield structure for horizontal cryogenic cold boxes. Its advantages are as follows: By employing a modular structure consisting of multiple layered cold shield units spliced ​​together and secured to the inner wall of the outer shell using studs and nuts, it successfully solves the problem of installing integral cold shields in large horizontal cold boxes due to limited internal space. Simultaneously, the mechanical rigid connection formed by studs and nuts ensures that the cold shield will not loosen or fall off during transportation and operation, guaranteeing the long-term stability of the structure. Furthermore, the gaps between the cold shield units and the outer shell, as well as the PTFE gaskets at the connection points, maintain a stable insulation space and effectively block thermal bridge conduction through the fixing points. This significantly reduces system heat loss while achieving convenient installation and reliable fixation, ultimately improving insulation performance and reducing energy consumption. Attached Figure Description

[0017] Figure 1 This is a structural cross-sectional view of an embodiment of the present utility model.

[0018] Explanation of reference numerals in the attached drawings: 1. Outer shell body; 2. Stud weld nail; 3. Cold shield unit; 31. Mirror aluminum foil; 32. Insulation layer; 4. PTFE gasket; 5. Nut. Detailed Implementation

[0019] Typical embodiments embodying the features and advantages of this utility model will be described in detail in the following description. It should be understood that this utility model can have various variations in different embodiments, all of which do not depart from the scope of this utility model, and the descriptions and illustrations therein are for illustrative purposes only and not intended to limit this utility model.

[0020] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] To further illustrate the principle and structure of this utility model, the preferred embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0022] The core concept of this utility model lies in providing a "modular and assembleable" cold shield structure to solve the installation problem caused by the narrow internal space of large horizontal cold boxes.

[0023] like Figure 1 As shown, the present invention provides a modular cold shield structure for a horizontal low-temperature cold box, the basic components of which include an outer shell body 1 and a modular cold shield system disposed inside it.

[0024] The core of the modular cold shield system lies in the fact that it is not a single unit, but rather composed of multiple independent cold shield units 3 spliced ​​and covered on the inner peripheral wall of the outer shell 1. This "split-assembly" design is the prerequisite for this solution to be applied to horizontal structures.

[0025] The fixing of each cold shield unit 3 relies on a fixing system pre-set on the inner wall of the outer casing 1. The system mainly includes studs 2 arranged in an array at a certain interval (e.g., 400-600mm) and nuts 5 that cooperate with the studs 2.

[0026] Furthermore, to ensure insulation performance, a stable gap d must exist between the cold shield unit 3 and the inner wall of the outer casing 1. For this purpose, the present invention incorporates PTFE gaskets 4. These PTFE gaskets 4 can be positioned between the stud weld 2 and the cold shield unit 3, and / or between the inner wall of the outer casing 1 and the cold shield unit 3. Their function is to act as a spacer, ensuring the existence of the gap d, while simultaneously reducing heat conduction through the fixing point due to their low thermal conductivity.

[0027] The preferred fixing method is as follows: the cold shield unit 3 is pressed and fixed by studs 2 passing through it and nuts 5 tightened on the studs. The PTFE gasket 4 is compressed in this process, which provides stable support and also prevents loosening.

[0028] By adopting a modular structure consisting of multiple layered cold shield units spliced ​​together and secured to the inner wall of the outer shell using studs and nuts, the problem of installing a single cold shield in large horizontal cold boxes due to limited internal space has been successfully solved. Simultaneously, the mechanical rigid connection formed by studs and nuts ensures that the cold shield will not loosen or fall off during transportation and operation, guaranteeing the long-term stability of the structure. Furthermore, the gaps between the cold shield units and the outer shell, as well as the PTFE gaskets at the connection points, maintain a stable insulation space and effectively block thermal bridge conduction through the fixing points. This significantly reduces heat loss while achieving convenient installation and reliable fixation, ultimately improving insulation performance and reducing energy consumption.

[0029] For the cylindrical body of the cold box, the cold shield unit 3 can be designed as a regular rectangular or arc-shaped plate, which is convenient for material cutting and installation.

[0030] For the head of the cold box, the cold shield unit 3 needs to be spliced ​​and covered with a more complex shape. Specifically, it may include a circular unit located at the center of the head, and multiple fan-shaped units distributed around the circular unit, which are combined to perfectly fit the curved surface of the head.

[0031] Furthermore, the cold screen unit 3 itself is a layered structure. In a preferred embodiment, it includes a mirrored aluminum foil 31 and a heat insulation layer 32 stacked sequentially from the inside out (with the area closer to the outer shell as "outer" and the area closer to the inner container as "inner").

[0032] The mirror aluminum foil 31 is the core functional layer that constitutes the cold screen unit 3. Its main function is to use the high reflectivity of its surface to reflect the ambient heat radiation back, thereby significantly reducing radiative heat leakage. This is the basic principle of how the cold screen achieves its heat insulation function.

[0033] In a preferred embodiment of this invention, the mirror aluminum foil 31 is a single-sided mirror aluminum foil with a thickness of 0.3 mm. To ensure optimal reflection, during installation, the bright, highly reflective mirror surface must face inwards towards the interior of the cold chamber (i.e., towards the inward-facing low-temperature components), while the matte surface faces towards the outer casing 1. This orientation allows heat radiation from the relatively high-temperature casing wall to be effectively reflected by the mirror, thereby maximizing the blocking of heat outside the cold screen.

[0034] As a further optimization of this utility model, the cold shield unit 3 can be provided with two layers of mirrored aluminum foil. That is, a single-layer mirrored aluminum foil is stacked on both the inner and outer sides of the insulation layer 32. In this case, the outer aluminum foil faces inward to reflect the radiant heat of the outer shell wall; the inner aluminum foil also faces inward to reflect the radiant heat that may be generated by the internal low-temperature components. This "double-sided shielding" structure can construct a more complete radiation barrier, thereby achieving a better insulation effect. Regardless of whether the cold shield unit adopts a single-layer or double-layer mirrored aluminum foil structure, as long as it forms a modular cold shield through the fixing system, it falls within the protection scope of this utility model.

[0035] The function of the insulation layer 32 is to further block heat conduction. It can be composed of an aluminized film and insulated materials such as fiberglass paper and foam, and has an extremely low thermal conductivity.

[0036] To ensure a stable bond between the mirror aluminum foil 31 and the insulation layer 32, it is preferable to use stitching to secure them together. This method provides a reliable connection and avoids introducing additional thermal bridges. The insulation layer 32 is also preferably provided with multiple vent holes (not shown) to allow for rapid gas release during vacuuming, improving vacuuming efficiency. The vent holes can be angled at 45 degrees and have a diameter of [missing information]. 2-3mm, density per 100cm³ 2 No fewer than 5.

[0037] Furthermore, to ensure the radiation sealing of the entire cold shield system and prevent heat radiation from penetrating through gaps, the edges of adjacent cold shield units 3 overlap each other, with an overlap of 10-15mm being preferred. Aluminum foil tape can be used to seal the overlap to further ensure airtightness.

[0038] The nut 5 in the fixing system is an important optimization point. To minimize heat conduction (thermal bridge effect) caused by the metal nut, the nut 5 is made of an insulating material, such as engineering plastics like PTFE (polytetrafluoroethylene) or PEEK (polyetheretherketone). This "insulating nut" is one of the key details of this invention in reducing heat leakage.

[0039] In a more preferred embodiment, the nut 5 made of the insulation material can be a flange nut. The flange nut has an enlarged bearing surface, which can better fit with the PTFE gasket 4, resulting in more even force distribution when pressing the cold shield unit 3, more reliable locking, and less tendency to loosen.

[0040] This invention, through a core design of "modular segmentation" combined with a systematic approach of "mechanical clamping and fixing" and "low thermal conductivity spacing," successfully constructs a cold shield structure suitable for horizontal cryogenic cold boxes. This structure ensures installability in confined spaces, stability during transportation and use, and high-efficiency thermal insulation during long-term operation.

[0041] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the technical scope of the present utility model. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A modular cold shield structure for a horizontal low-temperature cold box, characterized in that, include: The outer shell body has multiple studs and weld pins on its inner wall; Nut, which mates with the stud weld pin; Multiple cold screen units, wherein the cold screen units are layered and spliced ​​together to cover the inner wall of the outer shell body; A gap is provided between the cold screen unit and the inner wall of the outer shell body; A PTFE gasket is disposed between the stud and the cold shield unit, and / or between the inner wall of the outer casing and the cold shield unit; The cold shield unit is secured by the studs and nuts that pass through it.

2. The modular cold screen structure according to claim 1, characterized in that, The cold screen unit includes a mirrored aluminum foil and an insulating layer stacked together.

3. The modular cold screen structure according to claim 2, characterized in that, The mirrored aluminum foil and the heat insulation layer are fixedly connected by stitching.

4. The modular cold screen structure according to claim 2, characterized in that, The insulation layer has multiple vent holes.

5. The modular cold screen structure according to claim 1, characterized in that, The edges of adjacent cold screen units overlap each other.

6. The modular cold screen structure according to claim 1, characterized in that, The stud is fitted with a nut, which is made of heat-insulating material.

7. The modular cold screen structure according to claim 6, characterized in that, The nut is a flange nut.

8. The modular cold screen structure according to claim 1, characterized in that, The cold shield unit includes rectangular or arc-shaped plates for covering the cylindrical body, and / or circular and fan-shaped units for covering the end cap.

9. The modular cold screen structure according to any one of claims 1 to 8, characterized in that, The studs are arranged in an array at a spacing of 400mm to 600mm on the inner wall of the outer casing.

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