Winding pipe type heat exchanger for reforming equipment

Abstract

A winding pipe type heat exchanger for reforming equipment comprises a vertically-arranged shell pass barrel, a gas phase inlet connecting pipe and a liquid phase inlet connecting pipe are arranged on the side wall of the lower portion of the shell pass barrel, and a lower pipe plate is arranged at the bottom of the shell pass barrel; the heat exchange tubes are vertically arranged in the shell pass barrel and spirally wound into a multi-layer spiral tube from inside to outside, and the lower end of each heat exchange tube is supported on the lower tube plate; the guide cylinder is vertically arranged in the lower space of the shell pass cylinder and sleeves the periphery of the outermost layer of spiral pipe, an annular cavity with the gas phase inlet connecting pipe is formed between the cylinder wall of the guide cylinder and the corresponding side wall of the shell pass cylinder, and the annular cavity is communicated with the inner space of the guide cylinder through a communication port arranged in the circumferential direction; the annular spraying pipe is arranged in the inner space of the guide cylinder in the circumferential direction, the spraying pipe is communicated with the liquid phase inlet connecting pipe, a plurality of spraying holes are formed in the spraying pipe in the circumferential direction at intervals, and the spraying holes are located above the communicating port.

Description

Technical Field

[0001] This utility model belongs to the field of heat exchanger technology, specifically relating to a wound tube heat exchanger for reforming equipment. Background Technology

[0002] Currently, in reforming equipment, the reaction feed (low temperature) generally flows through the tube side of the heat exchanger, while the reaction discharge (high temperature) flows through the shell side. This is mainly due to the following two considerations:

[0003] First, from the perspective of process calculation, the high-temperature medium flows through the shell side, and under the same heat load, the required heat exchange area is smaller;

[0004] Second, from a structural design perspective, a feed tube path is more conducive to achieving uniform gas and liquid phase distribution.

[0005] However, considering the differences in raw materials used, the high-temperature reaction discharge goes through the shell side, which is prone to coking due to uneven distribution of the shell side medium, and coking is not easy to clean. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a wound tube heat exchanger for reforming equipment to reduce the risk of coking, in light of the current state of the technology.

[0007] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a wound tube heat exchanger for reforming equipment, comprising:

[0008] A vertically arranged shell-side cylinder has a gas phase inlet pipe for gas phase medium input and a liquid phase inlet pipe for liquid phase medium input on the lower side wall of the shell-side cylinder, and a lower tube sheet is provided at the bottom of the shell-side cylinder.

[0009] Multiple heat exchange tubes are vertically arranged inside the shell-side cylinder and spirally wound from the inside out to form a multi-layer spiral tube, with the lower end of each heat exchange tube supported by the lower tube sheet.

[0010] Its characteristic is that it also includes:

[0011] The guide tube is vertically installed in the lower space of the shell-side tube and is fitted around the outer periphery of the outermost spiral tube. The tube wall of the guide tube and the corresponding side wall of the shell-side tube form an annular cavity with the gas phase inlet pipe mentioned above. The annular cavity is connected to the internal space of the guide tube through a circumferentially arranged communication port.

[0012] An annular spray pipe is arranged circumferentially inside the guide tube. The spray pipe is connected to the liquid phase inlet pipe, and multiple spray holes are spaced circumferentially on the spray pipe, with each spray hole located above the connecting port.

[0013] By setting up the guide tube and spray pipe, during heat exchange, the gaseous medium input from the gas inlet pipe is pre-distributed in the annular cavity, and then enters the internal space of the guide tube through the circumferentially arranged connecting port. It then mixes with the liquid medium sprayed from the spray holes of the spray pipe and flows upward together to exchange heat with the heat exchange tube. This achieves full mixing of the shell-side gas and liquid media, ensures heat exchange effect, and reduces the risk of coking.

[0014] The design of this flow guide tube has two main advantages: First, it enables the guidance and pre-distribution of the gaseous medium. Second, due to the large diameter of the shell-side cylinder, when the gas flow rate is low, the velocity after gas-liquid mixing is low, which can easily lead to re-separation of the fully mixed gas and liquid phases. Because the cross-sectional area of ​​the flow guide tube is limited, it ensures the velocity after gas-liquid mixing, thereby guaranteeing thorough mixing of the two phases.

[0015] Preferably, the spray holes of the spray pipe face the spiral pipe.

[0016] To further improve the mixing of the gas and liquid phases, preferably, a gap is formed between adjacent heat exchange tubes, and the spray holes of the spray tube face the gap. This allows the sprayed liquid medium to mix with the gas medium in the gap.

[0017] Furthermore, the multiple heat exchange tubes are arranged in a rectangular array in cross-section, and the gaps include a first gap extending along the length direction of the rectangular array and a second gap extending along the width direction of the rectangular array.

[0018] The spray holes on the spray pipe are divided into at least two groups, with at least one group of spray holes facing the first gap and at least one group of spray holes facing the second gap.

[0019] A rectangular array arrangement ensures the required number of heat exchange tubes while simultaneously creating first and second gaps to facilitate the entry of liquid media. For example, liquid media sprayed from the spray holes can enter the first and second gaps and mix with the gaseous media within them. The design of the first and second gaps promotes the flow and mixing of the media.

[0020] In the above scheme, preferably, there are at least two spray pipes, respectively located between adjacent spiral tubes and / or between the guide tube and the outermost spiral tube. This ensures that the liquid medium is sprayed evenly into each guide tube. When the spray pipe is located between the guide tube and the outermost spiral tube, it serves two purposes: firstly, it distributes the liquid medium; secondly, it prevents the guide tube and the outermost spiral tube from directly contacting and wearing down the heat exchange tube. The spray pipe only makes point contact with the outermost spiral tube, thus protecting the heat exchange tube.

[0021] The above-mentioned spray pipes can be arranged concentrically inside and outside, and further, the spray pipes can be arranged at intervals along the vertical direction.

[0022] Furthermore, each spray pipe is connected to the liquid phase inlet pipe via a main pipe.

[0023] The aforementioned connecting ports can be arranged at intervals or continuously in the circumferential direction.

[0024] To form a connection port, a through hole can be made in the lower part of the guide tube wall. Preferably, the lower end of the guide tube is located above the lower tube sheet, and the two are arranged at intervals to form the connection port. In this way, the gaseous medium in the annular cavity can enter the guide tube more smoothly.

[0025] In the above embodiments, preferably, the lower part of the spiral tube has a vertically extending and spirally wound spiral segment, a straight pipe segment located below the spiral segment and extending vertically, and a connecting segment connecting the straight pipe segment and the spiral segment. The diameter of the straight pipe segment is smaller than the diameter of the spiral segment, and the lower end of the straight pipe segment is supported by the lower tube plate.

[0026] The spray pipe is set in the straight section corresponding to the spiral pipe.

[0027] Preferably, the shape of the guide tube matches the lower shape of the spiral tube.

[0028] Compared with the prior art, the advantages of this utility model are as follows: by setting up the guide tube and spray pipe, during heat exchange, the gaseous medium input from the gas inlet pipe is pre-distributed in the annular cavity, and then enters the internal space of the guide tube through the circumferentially arranged connecting port. Then it mixes with the liquid medium sprayed from the spray hole of the spray pipe and flows upward together to exchange heat with the heat exchange tube. This achieves full mixing of the shell-side gas and liquid media while ensuring the heat exchange effect and reducing the risk of coking.

[0029] The design of this flow guide tube has two main advantages: First, it enables the guidance and pre-distribution of the gaseous medium. Second, due to the large diameter of the shell-side cylinder, when the gas flow rate is low, the velocity after gas-liquid mixing is low, which can easily lead to re-separation of the fully mixed gas and liquid phases. Because the cross-sectional area of ​​the flow guide tube is limited, it ensures the velocity after gas-liquid mixing, thereby guaranteeing thorough mixing of the two phases. Attached Figure Description

[0030] Figure 1 This is a partial structural cross-sectional view of the wound tube heat exchanger according to an embodiment of the present invention;

[0031] Figure 2 for Figure 1 A sectional view;

[0032] Figure 3 for Figure 2 Enlarged view of section A in the middle;

[0033] Figure 4This is a cross-sectional view of a spray pipe located between spiral pipes 20 in adjacent layers according to an embodiment of the present invention;

[0034] Figure 5 This is a cross-sectional view of the spray pipe located between the guide tube 3 and the outermost spiral tube 20 in an embodiment of the present invention. Detailed Implementation

[0035] like Figures 1-5 As shown, this is a preferred embodiment of a wound tube heat exchanger for a reforming equipment according to the present invention. The wound tube heat exchanger includes a shell-side cylinder 1, a heat exchange tube 2, a guide tube 3, and a spray pipe 4.

[0036] The shell-side cylinder 1 is vertically arranged. The lower side wall of the shell-side cylinder 1 is provided with a gas phase inlet pipe 11 for gas phase medium input and a liquid phase inlet pipe 12 for liquid phase medium input (the upper part of the shell-side cylinder 1 is provided with a shell-side outlet pipe for shell-side medium output; this embodiment only shows the structure of the lower part of the heat exchanger, and the upper part of the heat exchanger is a conventional design, so it is not shown in the figure). The bottom of the shell-side cylinder 1 is provided with a lower tube sheet 13.

[0037] Multiple heat exchange tubes 2 are vertically arranged inside the shell-side cylinder 1 and are spirally wound from the inside out to form a multi-layer spiral tube 20. The lower part of the spiral tube 20 has a vertically extending and spirally wound spiral section 21, a straight tube section 22 located below the spiral section 21 and extending vertically, and a connecting section 23 connecting the straight tube section 22 and the spiral section 21. The diameter of the straight tube section 22 is smaller than the diameter of the spiral section 21, and the lower end of the straight tube section 22 is supported on the lower tube sheet 13. The diameter of the connecting section 23 gradually decreases from top to bottom.

[0038] The guide tube 3 is vertically positioned within the lower space of the shell-side tube 1 and is fitted around the outermost spiral tube 20, with the shape of the guide tube 3 matching the lower shape of the spiral tube 20. An annular cavity 30 with the aforementioned gas inlet pipe 11 is formed between the wall of the guide tube 3 and the corresponding side wall of the shell-side tube 1. The top of the annular cavity 30 is closed, and the bottom of the annular cavity 30 is connected to the internal space of the guide tube 3 via a circumferentially arranged connecting port 31. In this embodiment, the lower end of the guide tube 3 is located above the lower tube sheet 13, and the two are spaced apart to form the aforementioned connecting port 31. The gaseous medium entering through the gas inlet pipe is distributed within the annular cavity, then enters the guide tube through the connecting port 31, and flows upward within the guide tube.

[0039] An annular spray pipe 4 is circumferentially disposed within the internal space of the guide tube 3 and corresponds to the straight pipe section 22 of the spiral tube 20. The spray pipe 4 is connected to the liquid phase inlet pipe 12, and multiple spray holes 40 are spaced circumferentially on the spray pipe 4. Each spray hole 40 is located above the connecting port 31 and faces the spiral tube 20. In this embodiment, a gap is formed between adjacent heat exchange tubes 2, and the spray holes 40 of the spray pipe 4 face the gap. Specifically, as shown... Figure 3 As shown, multiple heat exchange tubes 2 are arranged in a rectangular array in cross-section, with gaps including a first gap 201 extending along the length of the rectangular array and a second gap 202 extending along the width of the rectangular array; the spray holes 40 on the spray tube 4 are divided into two groups, with the first group of spray holes 4a facing the first gap 201 and the second group of spray holes 4b facing the second gap 202. Figure 3 As indicated by the middle arrow, the liquid medium sprayed from the first set of spray holes 4a and the second set of spray holes 4b enters the first gap 201 and the second gap 202 respectively, and mixes thoroughly with the gas medium in the first gap 201 and the second gap 202 to improve the gas-liquid mixing effect.

[0040] In this embodiment, as Figure 1 As shown, there are multiple spray pipes 4, one of which is located between the guide tube 3 and the outermost spiral tube 20. The other spray pipes are located between their respective adjacent spiral tubes 20. The number of other spray pipes can be designed according to the size of the heat exchanger, the gas-liquid phase mixing conditions, etc. While meeting the gas-liquid phase mixing requirements, the number of spray pipes should be minimized to reduce the diameter of the lower tube sheet. In this embodiment, the spray pipes 4 are arranged at intervals along the vertical direction. Each spray pipe 4 is connected to the liquid phase inlet pipe 12 via a main pipe 41.

[0041] Simultaneously, the orientation and number of spray nozzle openings can be designed according to the gas-liquid phase mixing conditions. In this embodiment, for example... Figure 4 As shown, the spray holes 40 on the spray pipe 4 located between the spiral pipes 20 of adjacent layers are inclined upwards, and there are two spray holes 40 on the cross-section of the spray pipe 4, which face the spiral pipes on both sides respectively. Figure 5 As shown, the spray holes 40 on the spray pipe 4 located between the guide tube 3 and the outermost spiral tube 20 can face the outermost spiral tube directly or be tilted upwards.

[0042] The term "vertical" is used in the specification and claims of this utility model, meaning basically along the up-down direction, and is not limited to just the vertical direction, but can also be slightly deviated from the vertical direction.

Claims

1. A wound tube heat exchanger for a reforming equipment, comprising: A vertically arranged shell-side cylinder (1) is provided with a gas phase inlet pipe (11) for gas phase medium input and a liquid phase inlet pipe (12) for liquid phase medium input on the lower side wall of the shell-side cylinder (1). A lower tube sheet (13) is provided at the bottom of the shell-side cylinder (1). Multiple heat exchange tubes (2) are vertically arranged inside the shell-side cylinder (1) and spirally wound from the inside out to form a multi-layer spiral tube (20), and the lower end of each heat exchange tube (2) is supported on the lower tube sheet (13). characterized in that It also includes: The guide tube (3) is vertically disposed in the lower space of the shell-side cylinder (1) and sleeved on the outer periphery of the outermost spiral tube (20). The cylinder wall of the guide tube (3) and the side wall of the corresponding shell-side cylinder (1) form an annular cavity (30) with the gas phase inlet pipe (11) mentioned above. The annular cavity (30) is connected to the internal space of the guide tube (3) through a circumferentially arranged communication port (31). An annular spray pipe (4) is arranged circumferentially in the internal space of the guide tube (3). The spray pipe (4) is connected to the liquid phase inlet pipe (12), and a plurality of spray holes (40) are arranged circumferentially on the spray pipe (4). Each spray hole (40) is located above the connecting port (31).

2. The spiral wound heat exchanger of claim 1, wherein: The spray holes (40) of the spray pipe (4) face the spiral pipe (20).

3. The spiral wound heat exchanger of claim 2, wherein: A gap is formed between adjacent heat exchange tubes (2), and the spray holes (40) of the spray tube (4) face the gap.

4. The spiral wound heat exchanger of claim 3, wherein: Multiple heat exchange tubes (2) are arranged in a rectangular array in cross-section, and the gaps include a first gap (201) extending along the length direction of the rectangular array and a second gap (202) extending along the width direction of the rectangular array. Each spray hole (40) on the spray pipe (4) is divided into at least two groups, with at least one group of spray holes facing the first gap (201) and at least one group of spray holes facing the second gap (202).

5. The spiral wound heat exchanger of claim 1, wherein: There are at least two spray pipes (4), which are respectively located between the spiral pipes (20) of adjacent layers or / and between the guide tube (3) and the outermost spiral pipe (20).

6. The spiral wound heat exchanger of claim 5, wherein: Each of the spray pipes (4) is arranged at intervals in the vertical direction.

7. The spiral wound heat exchanger of claim 5, wherein: Each of the spray pipes (4) is connected to the liquid phase inlet pipe (12) through the main pipe (41).

8. The wound tube heat exchanger according to claim 1, characterized in that: The lower end of the guide tube (3) is located above the lower tube sheet (13), and the two are arranged at intervals to form the communication port (31).

9. The spiral wound heat exchanger according to any one of claims 1 to 8, characterized in that: The lower part of the spiral tube (20) has a vertically extending and spirally wound spiral section (21), a straight tube section (22) located below the spiral section (21) and extending vertically, and a connecting section (23) connecting the straight tube section (22) and the spiral section (21). The diameter of the straight tube section (22) is smaller than the diameter of the spiral section (21), and the lower end of the straight tube section (22) is supported on the lower tube plate (13). The spray pipe (4) is set in the straight section (22) of the spiral pipe (20).

10. The spiral wound heat exchanger of claim 9, wherein: The shape of the guide tube (3) matches the lower shape of the spiral tube (20).

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