A natural gas cold box

Abstract

This utility model belongs to the technical field of natural gas cold boxes, and discloses a natural gas cold box, including an outer shell with an internal insulation layer. The outer shell is detachably mounted via a connecting flange assembly. A composite heat exchange unit is installed inside the outer shell, comprising an inner spiral tube and an outer baffle tube arranged coaxially. A maintenance passage is formed between the outer shell and the composite heat exchange unit, and a sliding mirror reflector is provided on the maintenance passage. The connecting flange assembly includes fixing holes, a self-sealing ring, fixing bolts, and fixing nuts. The outer baffle tube is made of aluminum alloy and has several baffle plates equidistantly arranged along the axial / circumferential direction of the outer baffle tube. The baffle plates are made of corrugated stainless steel. By setting up the composite heat exchange unit, the inner spiral tube enhances turbulence through spiral flow, improving the heat exchange effect, while the outer baffle tube guides the airflow to a uniform distribution, avoiding local overheating / overcooling, thus achieving efficient heat exchange.

Description

Technical Field

[0001] This utility model relates to the field of natural gas cold box technology, and in particular to a natural gas cold box. Background Technology

[0002] Natural gas cold boxes are key equipment in the natural gas processing and liquefaction process. They are mainly used to cool, liquefy and separate components of gas in a low-temperature environment. The principle is based on the phase change differences of different components at low temperatures.

[0003] Natural gas cold boxes cool natural gas to its liquefaction temperature (approximately -162°C) through low-temperature heat exchange (typically using processes such as expansion refrigeration or mixed refrigerant circulation), while simultaneously separating components such as methane and ethane. Currently, traditional natural gas cold boxes mostly employ shell-and-tube heat exchange structures, which suffer from low heat exchange efficiency and high maintenance costs. Therefore, we propose a new type of natural gas cold box. Utility Model Content

[0004] In view of the fact that most existing natural gas cold boxes adopt shell-and-tube heat exchange structures, which have problems such as low heat exchange efficiency and high maintenance costs, this utility model is proposed.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0006] A natural gas cold box includes an outer shell, an insulation jacket installed inside the outer shell, the outer shell being detachably mounted via a connecting flange assembly, and a composite heat exchange unit provided inside the outer shell, the composite heat exchange unit including an inner spiral tube and an outer baffle tube arranged coaxially;

[0007] A maintenance channel is formed between the outer shell and the composite heat exchange unit, and a sliding mirror reflector is provided on the maintenance channel.

[0008] As a technical solution for a natural gas cold box according to the present utility model, the connecting flange assembly includes a fixing hole, a self-sealing ring, fixing bolts, and fixing nuts on the flange.

[0009] As a technical solution for a natural gas cold box according to this utility model, the outer baffle is made of aluminum alloy.

[0010] As a technical solution for a natural gas cold box according to the present utility model, the outer baffle cylinder is provided with a plurality of baffle plates, and the plurality of baffle plates are equidistantly arranged along the axial / circumferential direction of the outer baffle cylinder, and the baffle plates are made of corrugated stainless steel plates.

[0011] As a technical solution of the natural gas cold box of this utility model, the baffle plate has a flow guide hole at the crest, and the spacing of the flow guide hole is set to decrease along the airflow direction.

[0012] As a technical solution of the natural gas cold box of this utility model, a guide plate is installed in the maintenance channel, and the guide plate is installed on the insulation layer.

[0013] The guide plate has a guide slot corresponding to the mirror reflector, and the guide slot is adapted to the mirror reflector. The mirror reflector can be slidably installed on the maintenance channel through the guide slot and the guide plate.

[0014] As a technical solution of the natural gas cold box of this utility model, a liquid accumulation chamber is installed at the bottom of the outer shell and the liquid accumulation chamber is connected to the outer shell. A siphon pipe is installed on the liquid accumulation chamber and the siphon pipe is connected to the liquid accumulation chamber. The liquid accumulation chamber is connected to an external discharge valve through the siphon pipe.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] 1. This utility model, by setting up a composite heat exchange unit, uses the inner spiral tube to enhance turbulence through spiral flow and improve the heat exchange effect, while the outer baffle guides the airflow to be evenly distributed to avoid local overheating / overcooling, so as to achieve efficient heat exchange.

[0017] 2. This utility model, by setting up a connecting flange assembly, an inspection channel, and a sliding mirror reflector, can achieve disassembly-free inspection and rapid maintenance, while significantly reducing operation and maintenance risks and costs. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0020] Figure 2 This is a schematic diagram of the outer shell of this utility model in its separated state.

[0021] Figure 3 For the present utility model Figure 2 Enlarged structural diagram at point A in the middle.

[0022] Figure 4 This is a cross-sectional structural diagram of the composite heat exchange unit of this utility model.

[0023] Figure 5For the present utility model Figure 4 Enlarged structural diagram at point B.

[0024] Explanation of reference numerals in the attached figures:

[0025] In the diagram: 1. Outer shell; 101. Insulation interlayer; 102. Liquid accumulation chamber; 103. Siphon pipe; 2. Connecting flange assembly; 301. Inner spiral tube; 302. Outer baffle; 303. Baffle plate; 304. Guide hole; 4. Maintenance passage; 401. Guide plate; 402. Guide groove; 5. Mirror reflector. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0028] Meanwhile, the meaning of "and / or" or "and / or" appearing throughout the text is that it includes three options. Taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0029] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0030] Reference Figures 1-5A natural gas cold box is provided, which includes an outer shell 1. An insulation jacket 101 is installed inside the outer shell 1. The insulation jacket 101 is filled with nano-aerogel felt with a thickness of 50-80mm. The outer shell 1 is detachable through a connecting flange assembly 2 to achieve modular assembly and quick maintenance, reducing downtime. The outer shell 1 is equipped with a composite heat exchange unit, which includes an inner spiral tube 301 and an outer baffle 302 arranged coaxially. The inner spiral tube 301 is made of seamless copper-nickel alloy tube with a spiral angle of 30°-45°. The spiral flow of the inner spiral tube 301 enhances turbulence and improves the heat exchange effect. The outer baffle 302 guides the airflow to be evenly distributed to avoid local overheating / overcooling.

[0031] The outer casing 1 forms a maintenance channel 4 between the composite heat exchange unit and the maintenance channel 4. A sliding mirror reflector 5 is provided on the maintenance channel 4. The surface of the mirror reflector 5 can be plated with a gold film. The internal condition can be observed through the mirror reflector 5 without disassembly, which significantly reduces the difficulty of maintenance and safety hazards.

[0032] Reference Figure 1 and Figure 2 The connecting flange assembly 2 includes a fixing hole, a self-sealing ring, fixing bolts, and fixing nuts on the flange to ensure the sealing reliability of the flange under low temperature contraction conditions and prevent natural gas leakage.

[0033] Reference Figure 2 , Figure 4 and Figure 5 The outer baffle 302 is made of aluminum alloy. The outer baffle 302 uses a 6061-T6 aluminum alloy cylinder body with anodized inner wall. The gap between the cylinder body and the spiral tube is 10-15mm. In application, the aluminum alloy outer baffle 302 has both high thermal conductivity and low temperature toughness, improves the heat exchange rate and adapts to extreme environments of -162℃.

[0034] Reference Figure 2 , Figure 4 and Figure 5 The outer baffle 302 is provided with several baffles 303, and the baffles 303 are equidistantly arranged along the axial / circumferential direction of the outer baffle 302. The baffles 303 are made of corrugated stainless steel plates to increase the heat exchange area, induce fluid turbulence, and improve the heat transfer coefficient.

[0035] Reference Figure 2 , Figure 4 and Figure 5 The baffle 303 has flow guide holes 304 at the crests, and the spacing of the flow guide holes 304 is set to decrease along the airflow direction. The decreasing hole spacing optimizes the airflow distribution, reduces pressure drop loss, and avoids the decrease in heat exchange efficiency caused by downstream flow velocity attenuation.

[0036] Reference Figure 2 and Figure 4 A guide plate 401 is installed in the maintenance passage 4, and the guide plate 401 is installed on the insulation interlayer 101.

[0037] The guide plate 401 has a guide slot 402 corresponding to the mirror reflector 5, and the guide slot 402 is adapted to the mirror reflector 5. The mirror reflector 5 can be slidably installed on the maintenance channel 4 through the guide slot 402 and the guide plate 401. The guide slot 402 accurately positions the mirror reflector 5, ensuring a stable inspection angle and improving maintenance convenience.

[0038] Reference Figure 1 and Figure 2 The bottom of the outer casing 1 is equipped with a liquid collection chamber 102, which is connected to the outer casing 1. A siphon tube 103 is installed on the liquid collection chamber 102 and is connected to the liquid collection chamber 102. The liquid collection chamber 102 is connected to an external discharge valve through the siphon tube 103. In application, the liquid collection chamber 102 and the siphon tube 103 automatically collect and discharge low-temperature condensate (such as heavy hydrocarbons and water) to prevent pipe blockage or equipment corrosion.

[0039] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A natural gas cold box characterized by: Includes an outer shell (1), an insulating interlayer (101) is installed inside the outer shell (1), the outer shell (1) is detachably installed via a connecting flange assembly (2), and a composite heat exchange unit is provided inside the outer shell (1), the composite heat exchange unit includes an inner spiral tube (301) and an outer baffle tube (302) arranged coaxially. A maintenance channel (4) is formed between the outer shell (1) and the composite heat exchange unit, and a sliding mirror reflector (5) is provided on the maintenance channel (4).

2. The natural gas cold box of claim 1, wherein: The connecting flange assembly (2) includes a fixing hole, a self-sealing ring, fixing bolts, and fixing nuts on the flange.

3. The natural gas cold box of claim 1, wherein: The outer baffle (302) is made of aluminum alloy.

4. The natural gas cold box according to claim 1, characterized in that: The outer baffle cylinder (302) is provided with a plurality of baffle plates (303), and the plurality of baffle plates (303) are equidistantly arranged along the axial / circumferential direction of the outer baffle cylinder (302). The baffle plates (303) are made of corrugated stainless steel plates.

5. The natural gas cold box of claim 4, wherein: The baffle plate (303) has a flow guide hole (304) at the crest, and the spacing of the flow guide hole (304) decreases along the airflow direction.

6. The natural gas cold box of claim 1, wherein: The maintenance passage (4) is equipped with a guide plate (401), and the guide plate (401) is installed on the insulation interlayer (101); The guide plate (401) has a guide slot (402) corresponding to the mirror reflector (5), and the guide slot (402) is adapted to the mirror reflector (5). The mirror reflector (5) can be slidably installed on the maintenance channel (4) through the guide slot (402) and the guide plate (401).

7. The natural gas cold box of any one of claims 1-6, wherein: The bottom of the outer shell (1) is provided with a liquid accumulation chamber (102), and the liquid accumulation chamber (102) is connected to the outer shell (1). A siphon tube (103) is installed on the liquid accumulation chamber (102), and the siphon tube (103) is connected to the liquid accumulation chamber (102). The liquid accumulation chamber (102) is connected to an external discharge valve through the siphon tube (103).

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