Flow splitter and tube heat exchanger

Abstract

This utility model discloses a flow-dividing mechanism and a shell-and-tube heat exchanger, relating to the field of heat exchanger technology. Its main purpose is to uniformly divide the fluid while avoiding particle blockage in the tube box. The main technical solution of this utility model is: a flow-dividing mechanism, comprising: an inlet pipe and multiple baffles; the inlet pipe is connected to the inlet tube box of the shell-and-tube heat exchanger; the multiple baffles are spirally arranged along the axial direction of the inlet pipe on the inner wall of the inlet pipe.

Description

Technical Field

[0001] This utility model relates to the field of heat exchanger technology, and in particular to a flow splitting mechanism and a tube heat exchanger. Background Technology

[0002] In shell-and-tube heat exchangers, the tube-side fluid (such as cooling water or process media) must enter the heat exchange tube bundle through the inlet tube box. In actual operation, it has been found that due to the abrupt change in cross-sectional area between the inlet tube box and the heat exchange tube bundle (the cross-sectional area of ​​the tube box is much larger than that of a single heat exchange tube), the following problems easily occur when the fluid enters the tube bundle:

[0003] 1. The flow velocity in the heat exchange tubes near the center of the tube box is too high (even exceeding the design value), which leads to an increase in local pressure drop and energy consumption.

[0004] Second, the flow velocity of the heat exchange tubes at the edge of the tube box is too low (or even a "dead zone" appears), resulting in wasted heat exchange area and reduced overall efficiency.

[0005] The common solutions and drawbacks of the above problems in the existing technology are described below:

[0006] The guide plate structure is adopted: the inclined guide plate is set in the tube box to guide the fluid, but the guide plate is easily worn by the fluid and has poor adaptability to small diameter tube boxes.

[0007] Using a perforated distributor: a perforated plate is installed at the inlet of the pipe box to distribute the flow evenly, but the channels are easily blocked by particles in the medium, resulting in high maintenance costs. Utility Model Content

[0008] In view of this, the present invention provides a flow splitting mechanism and a tube heat exchanger, the main purpose of which is to avoid the problem of particle blockage in the tube box while uniformly splitting the fluid.

[0009] To achieve the above objectives, this utility model mainly provides the following technical solutions:

[0010] On the one hand, this utility model embodiment provides a diversion mechanism, which includes: an inlet pipe and multiple baffles;

[0011] The inlet pipe is connected to the inlet pipe box of the tube heat exchanger;

[0012] Multiple of the aforementioned baffle strips are spirally arranged on the inner wall of the water inlet pipe along the axial direction of the water inlet pipe.

[0013] The purpose of this utility model and the technical problems to be solved can be further achieved by the following technical measures.

[0014] Optionally, the spacing between two adjacent spoiler strips is equal.

[0015] Optionally, the radial cross-section of the spoiler strip is triangular or trapezoidal.

[0016] Optionally, the cross-sectional area of ​​each of the turbulence strips gradually increases along the flow direction of the fluid in the water inlet pipe.

[0017] Optionally, the height of the baffle strip is 2% to 5% of the inner diameter of the inlet pipe.

[0018] Optionally, the spacing between two adjacent spoiler strips is three to five times the height of the spoiler strip.

[0019] Optionally, the helix angle of the spoiler strip is 30° to 60°.

[0020] On the other hand, another embodiment of the present invention provides a shell-and-tube heat exchanger, which includes: an inlet tube box and the aforementioned flow splitting mechanism.

[0021] By employing the above technical solution, this utility model has at least the following advantages:

[0022] Due to the constraint of the spiral baffle, the water inside the inlet pipe flows spirally along the inner wall of the inlet pipe. When the water flows into the inlet pipe box through the inlet pipe, the water at the outlet end of the inlet pipe spirals out, generating radial diffusion, which evenly disperses the concentrated main fluid into multiple sub-flows, rather than relying on the guide plate to divide the flow.

[0023] This diversion mechanism uses spiral baffles instead of traditional guide plates, perforated plates or spiral guide vanes, resulting in a simpler structure (only requiring the processing or welding of strip-shaped protrusions on the inner wall of the inlet pipe), without complex channels or moving parts, and is less prone to clogging;

[0024] The height, spacing, and helix angle of the turbulence strips in this diversion mechanism can be adjusted according to parameters such as the inner diameter of the pipe section and the fluid velocity (Reynolds number) (for example, a larger helix angle is used for high-viscosity fluids and a smaller helix angle is used for low-viscosity fluids), making it widely applicable. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a heat exchanger provided in an embodiment of the present utility model;

[0026] Figure 2 A perspective view of a diversion mechanism provided for an embodiment of this utility model;

[0027] Figure 3 An axial view of a diversion mechanism provided for an embodiment of this utility model;

[0028] Figure 4 This is a diagram illustrating the working principle of the spoiler.

[0029] The reference numerals in the accompanying drawings include: inlet pipe 1, baffle strip 2, and inlet pipe box 3. Detailed Implementation

[0030] To further illustrate the technical means and effects adopted by this utility model to achieve its intended purpose, the specific implementation methods, structures, features, and effects according to this utility model application are described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0032] like Figures 1 to 3 As shown, an embodiment of the present invention provides a diversion mechanism, which includes: an inlet pipe 1 and a plurality of baffles 2;

[0033] The inlet pipe 1 is connected to the inlet pipe box 3 of the tube heat exchanger;

[0034] Multiple of the aforementioned baffle strips 2 are spirally arranged on the inner wall of the water inlet pipe 1 along the axial direction of the water inlet pipe 1.

[0035] The working process of the diversion mechanism is as follows:

[0036] Because of the constraint effect of the spiral baffle 2, the water inside the inlet pipe 1 flows spirally along the inner wall of the inlet pipe 1. When the water flows into the inlet pipe box 3 through the inlet pipe 1, the water at the outlet end of the inlet pipe 1 is spirally thrown out by centrifugal force, generating radial diffusion, which evenly disperses the concentrated main fluid into multiple sub-flows, rather than relying on the guide plate to divide the flow.

[0037] This diversion mechanism uses a spiral baffle 2 instead of a traditional guide plate, perforated plate or spiral guide vane, which has a simpler structure (only requires processing or welding strip-shaped protrusions on the inner wall of the inlet pipe 1), no complicated channels or moving parts, and is not easy to clog;

[0038] The height, spacing, and helix angle of the turbulence strips 2 in this diversion mechanism can be adjusted according to parameters such as the inner diameter of the pipe section and the fluid velocity (Reynolds number) (for example, a larger helix angle is used for high-viscosity fluids and a smaller helix angle is used for low-viscosity fluids), making it widely applicable.

[0039] In a specific embodiment, the spacing between two adjacent spoiler strips 2 is equal.

[0040] In this embodiment, the spacing between two adjacent turbulence strips 2 is equal. When the water flows out of the inlet pipe 1, the flow rates of the multiple sub-flows divided into the main fluid are uniform and equal, thereby making the water flow rates of the multiple heat exchange tube bundles relatively balanced.

[0041] In a specific embodiment, the radial cross-section of the spoiler strip 2 is triangular or trapezoidal.

[0042] In this embodiment, specifically, the radial cross-section of the baffle strip 2 is triangular or trapezoidal, and the base of the triangular or trapezoidal radial cross-section of the baffle strip 2 coincides with the inner wall of the inlet pipe 1. In the sub-flow between two adjacent baffle strips 2, the closer it is to the inner wall of the inlet pipe 1, the narrower the sub-flow width and the faster the flow velocity. The radial diffusion velocity of the sub-flow when it is thrown out to the inlet pipe box 3 is faster.

[0043] In a specific embodiment, the cross-sectional area of ​​each of the turbulence strips 2 gradually increases along the flow direction of the fluid in the water inlet pipe 1.

[0044] In this embodiment, specifically, the cross-sectional area of ​​the turbulence strip 2 is larger closer to the outlet end of the inlet pipe 1, that is, the radial cross-sectional area of ​​the inlet pipe 1 occupied by the fluid becomes smaller and smaller. However, the fluid in the inlet pipe 1 is continuously flowing, that is, the water flow rate in the inlet pipe 1 is stable and consistent. Thus, the water flow velocity at the outlet end of the inlet pipe 1 is greater than the water flow velocity at the inlet end of the inlet pipe 1. That is, the single sub-flow between adjacent turbulence strips 2 is in an accelerated state. When the single sub-flow leaves the inlet pipe 1, the water flow that is spirally thrown out is also accelerated to the maximum speed, thereby increasing the range of spiral diffusion of multiple sub-flows and further improving the water flow balance of multiple heat exchange tube bundles in the shell and tube heat exchanger.

[0045] In a specific embodiment, the height of the baffle strip 2 is 2% to 5% of the inner diameter of the water inlet pipe 1.

[0046] In this embodiment, specifically, the height of the baffle strip 2 is 2% to 5% of the inner diameter of the inlet pipe 1, which has a relatively small impact on the overall pressure drop of the inlet pipe 1.

[0047] In a specific embodiment, the spacing between two adjacent spoiler strips 2 is three to five times the height of the spoiler strip 2.

[0048] In this embodiment, specifically, the width of the sub-flow layer between two adjacent turbulence strips 2 is three to five times the height of the sub-flow layer, so that the spiral diffusion of multiple sub-flows is relatively stable within the inlet pipe box 3.

[0049] like Figure 4 As shown, in a specific embodiment, the helix angle of the spoiler strip 2 is 30° to 60°.

[0050] In this embodiment, specifically, if the helix angle is too small, the resistance to the water flow in the inlet pipe 1 will be too great, and the overall pressure drop in the inlet pipe 1 will be too great; if the helix angle is too large, when multiple sub-streams leave the inlet pipe 1, the range of the sub-streams spiraling out will be too small, which is not conducive to the uniform diffusion of the water flow.

[0051] like Figure 1As shown, another embodiment of the present invention provides a shell-and-tube heat exchanger, which includes: an inlet tube box 3 and the aforementioned diversion mechanism.

[0052] Specifically, taking circulating water as the pipe-side medium, with a temperature of 30℃, a flow velocity of 1.2m / s, and an inner diameter of 150mm at the inlet section of the pipe box as an example:

[0053] The length of water inlet pipe 1 is twice the inner diameter of water inlet pipe 1 (300mm);

[0054] The spoiler 2 is made of stainless steel and has a triangular cross-section (3mm at the base and 4mm in height).

[0055] The spiral angle α = 45°, and a total of 8 spiral-shaped baffles are set, with an adjacent spacing of 12mm (3 times the height of 4mm);

[0056] The installation of inlet pipe 1 and testing showed that the inlet flow velocity deviation of multiple heat exchanger tube bundles decreased from ±28% to ±7%, and the overall heat exchange efficiency of the heat exchanger increased by about 12%.

[0057] The flow distribution mechanism of this heat exchanger has no pores or narrow slits, so particles in the medium (such as solid impurities ≤2mm) can flow along with the fluid through the turbulence strip 2, and are not easy to accumulate and block.

[0058] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A flow splitting mechanism, characterized by, include: Water inlet pipe, which is connected to the inlet tube box of the tube heat exchanger; Multiple flow-dispersing strips are spirally arranged on the inner wall of the water inlet pipe along the axial direction of the water inlet pipe.

2. The diversion mechanism according to claim 1, characterized in that, The spacing between two adjacent spoiler strips is equal.

3. The diversion mechanism according to claim 1, characterized in that, The radial cross-section of the spoiler strip is triangular or trapezoidal.

4. The diversion mechanism according to claim 3, characterized in that, Along the flow direction of the fluid in the inlet pipe, the cross-sectional area of ​​each of the turbulence strips gradually increases.

5. The diversion mechanism according to claim 3, characterized in that, The height of the baffle strip is 2% to 5% of the inner diameter of the inlet pipe.

6. The diversion mechanism according to claim 5, characterized in that, The spacing between two adjacent spoiler strips is three to five times the height of the spoiler strip.

7. The diversion mechanism according to any one of claims 1 to 6, characterized in that, The helix angle of the spoiler strip is 30° to 60°.

8. A shell-and-tube heat exchanger, characterized by include: The inlet pipe box and the diversion mechanism as described in any one of claims 1 to 7.

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