Heat transfer enhancement structure, heat transfer enhancement tube, Preheating device and application

Abstract

The present application relates to a heat transfer enhancement structure, a heat transfer enhancement tube, a preheating device and application. The heat transfer enhancement structure comprises a coal water slurry tube and at least one protrusion distributed on the inner wall of the coal water slurry tube; the ratio of the height of the protrusion to the inner diameter of the coal water slurry tube is (1-8):50. The heat transfer enhancement tube comprises the heat transfer enhancement tube structure as described above. The preheating device comprises a shell and the heat transfer enhancement tube as described above located in the shell. The heat transfer enhancement structure of the present application is provided with protrusions on the inner wall of the coal water slurry tube, which is used as an inner wall surface modification to prevent the coal water slurry from blocking when flowing and to help enhance heat transfer.

Description

Technical Field

[0001] This invention relates to a heat transfer enhancement structure, a heat transfer enhancement tube, a preheating device, and its application. Background Technology

[0002] Coal gasification technology is one of the core technologies for the clean and efficient utilization of coal. The syngas produced by coal gasification can be used to develop coal-based chemicals (such as fertilizers, methanol, aromatics, olefins, ethylene glycol, etc.), coal-based fuels (such as natural gas and petroleum), and can be used for IGCC power generation, polygeneration systems, hydrogen production, etc.

[0003] Traditional fluidized bed gasification with wet feed involves processing coal into a coal-water slurry with a moisture content of approximately 40% using equipment such as a coal mill, and then feeding it into the gasifier via a slurry pump. Wet feed is beneficial for stable feedstock transport and pressurized gasification. However, because the coal-water slurry enters the gasifier at a low temperature (close to room temperature), while the temperature inside the gasifier exceeds 1200℃, the slurry absorbs a large amount of heat to raise its temperature upon entering the gasifier, requiring more energy and hindering the improvement of gasification efficiency.

[0004] Preheating technology for coal-water slurry is one of the effective methods to achieve high efficiency and low oxygen consumption in coal-water slurry gasification. Increasing the temperature of the coal-water slurry entering the gasifier can not only significantly reduce indicators such as specific coal consumption and specific oxygen consumption, but also reduce the viscosity of the coal-water slurry, thereby enhancing nozzle atomization and improving carbon conversion rate.

[0005] However, due to the complex rheological properties of coal-water slurry—it is a non-Newtonian slurry with high solid content and high viscosity—traditional preheating methods and equipment suffer from low preheating efficiency and susceptibility to clogging, making it difficult to meet the preheating requirements of coal-water slurry. In practice, there is an urgent need for a highly efficient coal-water slurry heat exchanger to preheat the slurry and improve its gasification efficiency. Summary of the Invention

[0006] The technical problem this invention aims to solve is to overcome the shortcomings of existing technologies, such as low preheating efficiency and susceptibility to clogging in coal-water slurry preheating, by providing a heat transfer enhancement structure, a heat transfer enhancement tube, a preheating device, and its application. This invention can rationally utilize the system's byproduct steam, thereby enhancing the preheating effect of coal-water slurry.

[0007] The present invention solves the above-mentioned technical problems through the following technical solution:

[0008] In a first aspect, the present invention provides a heat transfer enhancement structure comprising a coal-water slurry pipe and at least one protrusion distributed on the inner wall of the coal-water slurry pipe; the ratio of the height of the protrusion to the inner diameter of the coal-water slurry pipe is (1-8): 50.

[0009] In this invention, the ratio of the height of the protrusion to the inner diameter of the coal-water slurry pipe can be 3:50.

[0010] In this invention, the ratio of the thickness of the coal-water slurry pipe to the inner diameter of the coal-water slurry pipe can be 5:50.

[0011] In this invention, the protrusion is a modification of the inner wall surface of the coal-water slurry pipe, serving as a heat transfer enhancer for the coal-water slurry to prevent blockage during flow and to enhance heat transfer.

[0012] In this invention, the protruding structure is preferably a spherical cover.

[0013] In this invention, there may be multiple protrusions along the circumference of the inner wall of the coal-water slurry pipe. Preferably, the protrusions are evenly distributed along the circumference of the inner wall of the coal-water slurry pipe. Preferably, the number of protrusions along the circumference of the inner wall of the coal-water slurry pipe may be 4-16, for example, 10.

[0014] In this invention, at least one protrusion may also be distributed on the outer wall of the coal-water slurry pipe.

[0015] The bump is a vortex generator used to enhance the heat transfer of steam to the coal-water slurry pipe.

[0016] The ratio of the height of the protrusion to the inner diameter of the coal-water slurry pipe can be (5-25): 50, for example, 8: 50.

[0017] The protrusion can be elliptical in shape, i.e., a manifold vortex generator, and the height of the elliptical cylinder is the height of the protrusion.

[0018] The protrusion can be a triangular prism, an airfoil vortex generator, or a wedge-like object, with one side of the triangular prism connected to the outer wall of the coal-water slurry pipe.

[0019] Furthermore, the height direction of the triangular prism can be parallel to the radial direction of the coal-water slurry pipe.

[0020] Furthermore, the height of the triangular prism is equal to the width of the protrusion, and the ratio of this height to the inner diameter of the coal-water slurry pipe can be (3-15): 50, for example (4-9): 50.

[0021] Furthermore, the width of the surface connecting the triangular prism to the outer wall of the coal-water slurry pipe is equal to the length of the protrusion, and the ratio of this width to the inner diameter of the coal-water slurry pipe can be (3-15): 50, (8-9): 50.

[0022] The number of protrusions along the circumference of the outer wall of the coal-water slurry pipe can be multiple. Preferably, the protrusions are evenly distributed along the circumference of the outer wall of the coal-water slurry pipe. Preferably, the number of protrusions along the circumference of the outer wall of the coal-water slurry pipe can be 8-30, for example 19.

[0023] In this invention, the outer wall of the coal-water slurry pipe may also be provided with hollow annular fins.

[0024] The annular fins can be vertically connected to the outer wall of the coal-water slurry pipe.

[0025] The ratio of the height of the annular fin to the inner diameter of the coal-water slurry pipe can be (15-100): 50, for example, 60: 50.

[0026] The ratio of the thickness of the annular fin to the inner diameter of the coal-water slurry pipe can be 2:50.

[0027] The hollow area of ​​the annular fin can be 20%-50% of the total area of ​​the annular fin, for example, 35%.

[0028] The annular fin can be a porous fin. The ratio of the aperture of the porous fin to the height of the annular fin can be (5-45):60, for example, 25:60.

[0029] The annular fin can be serrated. The number of serrations on the serrated fin can be 8-20.

[0030] In this invention, the heat transfer enhancement structure can be made of carbon steel or stainless steel.

[0031] In a second aspect, the present invention provides a heat transfer enhanced tube, which includes the heat transfer enhanced tube structure as described above.

[0032] In this invention, the ratio of the spacing of the protrusions along the heat transfer enhancement tube to the height of the protrusions can be (1-10):1, for example 3:1.

[0033] In this invention, at least one protrusion may be distributed on the outer wall of the coal-water slurry pipe, and the ratio of the spacing of the protrusions along the heat transfer enhancement pipe to the length of the protrusions may be (1-10):1, for example 3:1.

[0034] In this invention, the outer wall of the coal-water slurry pipe may also be provided with hollow annular fins, and the ratio of the spacing of the annular fins along the heat transfer enhancement pipe to the inner diameter of the coal-water slurry pipe may be (5-500): 50, for example 50: 50.

[0035] In this invention, the heat transfer enhancement tube can be a spiral coil. The inlet and outlet of the spiral coil can be located on the same side.

[0036] Thirdly, the present invention provides a preheating device comprising a housing and a heat transfer enhancement tube as described above located within the housing.

[0037] In this invention, the overall shape of the outer shell can be a cylinder. Conventionally, the upper and lower ends of the outer shell are respectively provided with a steam inlet and a condensate outlet.

[0038] In this invention, the heat transfer enhancement tube can be a spiral coil, and the ratio of the diameter of the spiral coil to the inner diameter of the outer shell can be (1-2): 2.6. The ratio of the spacing between each layer of the spiral coil to the internal height of the outer shell can be (0.03-0.9): 3, for example, 0.3: 3.

[0039] In this invention, at least one circular baffle may be provided inside the outer shell. The central axis of the circular baffle may coincide with the central axis of the outer shell. The ratio of the diameter of the circular baffle to the inner diameter of the outer shell may be 1:(3-6), for example, 0.5:2.6. Multiple circular baffles may be provided, and the ratio of the distance between each circular baffle to the internal height of the outer shell may be (0.2-1.5):3, for example, 0.5:3. The ratio of the thickness of the circular baffle to the inner diameter of the coal-water slurry pipe may be 2:50.

[0040] In this invention, a spiral baffle may also be provided inside the outer shell. The central axis of the spiral baffle may coincide with the central axis of the outer shell. The ratio of the difference between the outer diameter and the inner diameter of the spiral baffle to the inner diameter of the outer shell may be 1:(1.5-3), for example, 1.6:2.6. The ratio of the pitch of the spiral baffle to the internal height of the outer shell may be (0.2-1.5):3, for example, 0.5:3. The ratio of the thickness of the spiral baffle to the inner diameter of the coal-water slurry pipe is 2:50.

[0041] In this invention, an annular baffle may also be provided inside the outer shell. The central axis of the annular baffle may coincide with the central axis of the outer shell. The ratio of the width of the annular baffle to the inner diameter of the outer shell may be 1:(2-6), for example, 1:2.6. The ratio of the thickness of the annular baffle to the inner diameter of the coal-water slurry pipe is 2:50.

[0042] In this invention, conventionally, the spiral baffle, the circular baffle, and the annular baffle can all be fixed inside the outer shell using a support frame.

[0043] In this invention, the baffle, the annular fins, and the protrusions constitute a steam heat transfer enhancer.

[0044] Fourthly, the present invention provides an application of the preheating device described above in preheated hot coal slurry.

[0045] In this invention, the concentration of the coal-water slurry can be 50%-70%, for example 62%, where the percentage is the ratio of the mass of coal in the coal-water slurry to the mass of the coal-water slurry.

[0046] In this invention, the viscosity of the coal-water slurry can be 300-1300 mPa·s, for example 600 mPa·s, and the viscosity test temperature is the feed temperature of the coal-water slurry.

[0047] In this invention, the flow velocity of the coal-water slurry in the heat transfer enhancement tube can be 0.1-3 m / s, for example 0.5 m / s.

[0048] In this invention, the preheating device can employ steam preheating. The steam can be by-product steam from the gasification system. Preferably, it is low-pressure flash steam generated by the low-pressure flash evaporator in the black water gasification system.

[0049] The positive and progressive effects of this invention are as follows:

[0050] (1) The heat transfer enhancement structure of the present invention has protrusions on the inner wall of the coal-water slurry pipe as an inner wall surface decoration to prevent blockage when the coal-water slurry flows, which helps to enhance heat transfer.

[0051] (2) The heat transfer enhancement structure of the present invention may also be provided with protrusions as eddy current generators to enhance the heat transfer of steam to the coal-water slurry pipe; and may also be provided with annular fins;

[0052] (3) The heat transfer enhancement tube of the present invention can be a coil structure with a certain curvature. The above structure combination enhances the preheating effect of coal-water slurry.

[0053] (4) The preheating device of the present invention can make reasonable use of the system by-product steam. In the subsequent coal gasification process, it can reduce the specific coal consumption and specific oxygen consumption, improve the efficiency of coal-water slurry gasification, reduce carbon emissions, produce crude coal gas with a high effective gas content, and have low energy consumption and carbon dioxide emissions. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the heat transfer enhancement structure in Example 1;

[0055] Figure 2 This is a schematic diagram of the water-coal slurry preheating device in Example 2;

[0056] Figure 3 This is a side sectional view of the coal-water slurry preheating device in Example 2;

[0057] Figure 4 This is a partial cross-sectional view of the coal-water slurry preheating device in Example 2;

[0058] Figure 5 This is a schematic diagram of the annular fin in Example 2;

[0059] Figure 6 This is a schematic diagram of the annular fins in other embodiments;

[0060] Figure 7This is a schematic diagram of the protrusion in Example 2;

[0061] Figure 8 This is a schematic diagram of the bump in other embodiments;

[0062] Figure 9 This is a schematic diagram of each baffle in Example 2;

[0063] The following are the labels in the diagram: heat transfer enhancement tube 1, coal-water slurry tube 10, protrusion 11, bump 12, annular fin 13, feed inlet 14, discharge outlet 15, outer shell 2, spiral baffle 21, circular baffle 22, annular baffle 23, steam inlet 24, condensate outlet 25. Detailed Implementation

[0064] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0065] Example 1

[0066] A heat transfer enhanced tube, comprising, for example Figure 1 The heat transfer enhancement structure shown includes a coal-water slurry pipe 10 and ten protrusions 11 evenly distributed on the inner wall of the coal-water slurry pipe 10. Each protrusion 11 has a spherical cap structure and a height of 3 mm. The inner diameter of the coal-water slurry pipe 10 is 50 mm, and the spacing between the protrusions 11 along the heat transfer enhancement pipe 1 is 9 mm.

[0067] Example 2

[0068] A coal-water slurry preheating device, such as Figure 2-3 The system includes a housing 2 and a heat transfer enhancement tube 1 located within the housing 2. The housing 2 is provided with a steam inlet 24 and a condensate outlet 25, and the heat transfer enhancement tube 1 is provided with a feed inlet 14 and a discharge outlet 15 at both ends, located on the same side. Both the housing 2 and the heat transfer enhancement tube 1 are made of stainless steel.

[0069] In this embodiment, as Figure 2 The heat transfer enhancement tube 1 is in the shape of a spiral coil, with the diameter of the spiral coil gradually increasing from 1 m to 2 m. The spacing between each layer of the spiral coil is 0.3 m, and the total length of the spiral coil inside the outer shell 2 is approximately 50 m. In this embodiment, the overall shape of the outer shell 2 is a cylinder with an inner diameter of 2.6 m and an internal height of 3 m.

[0070] In this embodiment, the heat transfer enhancement tube 1, as shown in the example... Figure 1The structure includes a heat transfer enhancement tube structure, which comprises a coal-water slurry pipe 10 and ten protrusions 11 evenly distributed on the inner wall of the coal-water slurry pipe 10. Each protrusion 11 has a spherical cap structure and a height of 3 mm. The inner diameter of the coal-water slurry pipe 10 is 50 mm, and the spacing between the protrusions 11 along the heat transfer enhancement tube 1 is 9 mm.

[0071] In this embodiment, the heat transfer enhancement structure also includes annular fins 13, such as... Figure 5 The outer wall of the coal-water slurry pipe 10 is also provided with porous annular fins 13. The annular fins 13 are perpendicularly connected to the outer wall of the coal-water slurry pipe 10. The annular fins 13 are porous fins, with a height of 60 mm, a thickness of 2 mm, a spacing of 50 mm along the heat transfer enhancement pipe 1, a hollow area of ​​35% of the total area, and a pore diameter of 25 mm. In other embodiments, the annular fins 13 may be serrated fins, such as... Figure 6 .

[0072] In this embodiment, the heat transfer enhancement structure further includes protrusions 12, such as... Figure 7 The outer wall of the coal-water slurry pipe 10 is also evenly distributed with nineteen protrusions 12. Each protrusion 12 is a triangular prism, with one side of the prism connected to the outer wall of the coal-water slurry pipe 10. The height of the prism is parallel to the radial direction of the coal-water slurry pipe 10. The height of each protrusion 12 is 8 mm, the width is 4 mm, and the length is 8 mm. The spacing between the protrusions 12 along the heat transfer enhancement pipe 1 is 24 mm. In other embodiments, the protrusions 12 are elliptical cylinders, such as... Figure 8 .

[0073] In this embodiment, as Figure 9 The outer casing 2 contains two circular baffles 22, the central axis of which coincides with the central axis of the outer casing 2. The diameter of the circular baffles 22 is 0.5 m, the distance between the two circular baffles 22 is 0.5 m, and the thickness of the circular baffles 22 is 2 mm. In this embodiment, the outer casing 2 also contains an annular baffle 23, the central axis of which coincides with the central axis of the outer casing 2. The outer diameter of the annular baffle 23 is equal to the inner diameter of the outer casing 2, the width of the annular baffle 23 is 1 m, and the thickness of the annular baffle 23 is 2 mm.

[0074] In this embodiment, a spiral baffle 21 is provided inside the outer shell 2. The central axis of the spiral baffle 21 coincides with the central axis of the outer shell 2. The inner diameter of the spiral baffle 21 is 1 m, the spiral width of the spiral baffle 21 is 1.6 m, the spiral pitch of the spiral baffle 21 is 0.5 m, and the thickness of the spiral baffle 21 is 2 mm. In this embodiment, the spiral baffle 21, the circular baffle 22, and the annular baffle 23 are all fixed inside the outer shell 2 by a support frame. The specific installation position is such that they do not have obvious contact with the heat transfer enhancement tube 1.

[0075] Example 3

[0076] Compared with Embodiment 2, this embodiment does not have protrusions 12.

[0077] Example 4

[0078] Compared with Example 2, this example does not have annular fins 13.

[0079] Example 5

[0080] Compared with Embodiment 2, this embodiment does not include the spiral baffle 21, the circular baffle 22, and the annular baffle 23.

[0081] Comparative Example 1

[0082] Compared with Example 2, this comparative example does not include protrusion 11, protrusion 12, annular fin 13, spiral baffle 21, circular baffle 22 and annular baffle 23.

[0083] Comparative Example 2

[0084] Compared with Example 2, in this comparative example, the height of protrusion 11 is too high, at 10 mm.

[0085] Application Example 1

[0086] The coal-water slurry preheating devices used in Examples 2-5 and Comparative Examples 1-2 were employed. The steam used for heating the coal-water slurry was low-flash steam, a byproduct of gasification, at approximately 140°C, with a flash steam consumption of 2.6 t / h. The coal-water slurry concentration was 62%, its viscosity was 600 mPa·s, its flow rate was 0.5 m / s, and its inlet temperature was 50°C. The heat transfer results are shown in the table below.

[0087]

[0088] Application Example 2

[0089] The coal-water slurry preheated by the coal-water slurry preheating device of Example 2 in Application Example 1 was used for gasification reaction at a gasification temperature of 1200°C and a pressure of 6.5 MPa.

[0090] The oxygen consumption of the preheated coal-water slurry during gasification is 358.3 Nm³. 3 / kNm 3 CO+H2, specific coal consumption is 546.8 kg / kNm 3 CO + H2; compared to the case without preheating, it saves 3.71% and 1.57% respectively, meaning that the specific oxygen consumption of the coal-water slurry without preheating during gasification is 372.1 Nm³. 3 / kNm 3 CO + H2, specific coal consumption is 555.6 kg / kNm 3 CO + H2.

[0091] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A preheating device, characterized in that, It includes a housing (2) and a heat transfer enhancement tube (1) located in the housing (2); the heat transfer enhancement tube (1) includes a heat transfer enhancement structure; The heat transfer enhancement structure includes a coal-water slurry pipe (10) and at least one protrusion (11) distributed on the inner wall of the coal-water slurry pipe (10); the ratio of the height of the protrusion (11) to the inner diameter of the coal-water slurry pipe (10) is (3-8):

50. The outer shell (2) is also provided with a spiral baffle (21); the central axis of the spiral baffle (21) coincides with the central axis of the outer shell (2); The outer shell (2) is also provided with at least one circular baffle (22); the central axis of the circular baffle (22) coincides with the central axis of the outer shell (2); The outer shell (2) is also provided with an annular baffle (23); the central axis of the annular baffle (23) coincides with the central axis of the outer shell (2); The preheating device is used in preheating hot coal slurry.

2. The preheating device according to claim 1, characterized in that, The ratio of the height of the protrusion (11) to the inner diameter of the coal-water slurry pipe (10) is 3:50; The ratio of the thickness of the coal-water slurry pipe (10) to the inner diameter of the coal-water slurry pipe (10) is 5:50; The protrusion (11) has a spherical cap structure; The number of protrusions (11) along the circumferential direction of the inner wall of the coal-water slurry pipe (10) is multiple; the protrusions (11) are evenly distributed along the circumferential direction of the inner wall of the coal-water slurry pipe (10); the number of protrusions (11) along the circumferential direction of the inner wall of the coal-water slurry pipe (10) is 4-16. The outer wall of the coal-water slurry pipe (10) is also provided with at least one protrusion (12); The outer wall of the coal-water slurry pipe (10) is also provided with hollow annular fins (13). The heat transfer enhancement structure is made of carbon steel or stainless steel.

3. The preheating device according to claim 2, characterized in that, The number of protrusions (11) along the circumference of the inner wall of the coal-water slurry pipe (10) is 10.

4. The preheating device according to claim 2, characterized in that, The ratio of the height of the protrusion (12) to the inner diameter of the coal-water slurry pipe (10) is (5-25): 50; The protrusion (12) is shaped like an elliptical cylinder, and the height of the elliptical cylinder is the height of the protrusion (12); The protrusion (12) is a triangular prism, one side of which is connected to the outer wall of the coal-water slurry pipe (10); the height of the triangular prism is parallel to the radial direction of the coal-water slurry pipe (10); the height of the triangular prism is the width of the protrusion (12), and the ratio of the height to the inner diameter of the coal-water slurry pipe (10) is (3-15): 50; the width of the surface of the triangular prism connected to the outer wall of the coal-water slurry pipe (10) is the length of the protrusion (12), and the ratio of the length to the inner diameter of the coal-water slurry pipe (10) is (3-15):

50. The number of protrusions (12) along the circumference of the outer wall of the coal-water slurry pipe (10) is multiple; the protrusions (12) are evenly distributed along the circumference of the outer wall of the coal-water slurry pipe (10); the number of protrusions (12) along the circumference of the outer wall of the coal-water slurry pipe (10) is 8-30. The annular fin (13) is perpendicularly connected to the outer wall of the coal-water slurry pipe (10); The ratio of the height of the annular fin (13) to the inner diameter of the coal-water slurry pipe (10) is (15-100): 50; The ratio of the thickness of the annular fin (13) to the inner diameter of the coal-water slurry pipe (10) is 2:50; The hollow area of ​​the annular fin (13) is 20%-50% of the total area of ​​the annular fin (13); The annular fin (13) is a porous fin; the ratio of the aperture of the porous fin to the height of the annular fin (13) is (5-45):

60. The annular fin (13) is serrated; the number of serrations on the serrated fin is 8-20.

5. The preheating device according to claim 4, characterized in that, The ratio of the length of the protrusion (12) to the inner diameter of the coal-water slurry pipe (10) is (8-9): 50; And / or, the height of the protrusion (12) is in the ratio of the inner diameter of the coal-water slurry pipe (10) to 8:

50.

6. The preheating device according to claim 4, characterized in that, The ratio of the height of the triangular prism to the inner diameter of the coal-water slurry pipe (10) is (4-9):

50.

7. The preheating device according to claim 4, characterized in that, The number of protrusions (12) along the circumference of the outer wall of the coal-water slurry pipe (10) is 19.

8. The preheating device according to claim 4, characterized in that, The ratio of the height of the annular fin (13) to the inner diameter of the coal-water slurry pipe (10) is 60:

50.

9. The preheating device according to claim 4, characterized in that, The hollow area of ​​the annular fin (13) is 35% of the total area of ​​the annular fin (13).

10. The preheating device according to claim 4, characterized in that, The ratio of the aperture of the porous fin to the height of the annular fin (13) is 25:

60.

11. The preheating device according to claim 1, characterized in that, The ratio of the spacing of the protrusions (11) along the heat transfer enhancement tube (1) to the height of the protrusions (11) is (1-10): 1; The outer wall of the coal-water slurry pipe (10) is also provided with at least one protrusion (12), and the ratio of the spacing of the protrusion (12) along the heat transfer enhancement pipe (1) to the length of the protrusion (12) is (1-10): 1; The outer wall of the coal-water slurry pipe (10) is also provided with hollow annular fins (13), and the ratio of the spacing of the annular fins (13) along the heat transfer enhancement pipe (1) to the inner diameter of the coal-water slurry pipe (10) is (5-500):

50. The heat transfer enhancement tube (1) is in the shape of a spiral coil; the inlet and outlet of the spiral coil are located on the same side.

12. The preheating device according to claim 11, characterized in that, The ratio of the spacing of the protrusions (11) along the heat transfer enhancement tube (1) to the height of the protrusions (11) is 3:

1.

13. The preheating device according to claim 11, characterized in that, The ratio of the spacing of the bumps (12) along the heat transfer enhancement tube (1) to the length of the bumps (12) is 3:

1.

14. The preheating device according to claim 11, characterized in that, The ratio of the spacing of the annular fins (13) along the heat transfer enhancement tube (1) to the inner diameter of the water-coal slurry tube (10) is 50:

50.

15. The preheating device according to claim 1, characterized in that, The outer shell (2) is cylindrical in shape; the upper and lower ends of the outer shell (2) are respectively provided with a steam inlet and a condensate outlet; The heat transfer enhancement tube (1) is in the shape of a spiral coil, and the ratio of the diameter of the spiral coil to the inner diameter of the outer shell (2) is (1-2): 2.6; the ratio of the spacing between each layer of the spiral coil to the internal height of the outer shell (2) is (0.03-0.9): 3; The ratio of the diameter of the circular baffle (22) to the inner diameter of the outer shell (2) is 1: (3-6); there are multiple circular baffles (22), and the ratio of the distance between each circular baffle (22) to the internal height of the outer shell (2) is (0.2-1.5): 3; the ratio of the thickness of the circular baffle (22) to the inner diameter of the coal-water slurry pipe (10) is 2:

50.

16. The preheating device according to claim 15, characterized in that, The ratio of the spacing between each layer of the spiral coil to the internal height of the outer shell (2) is 0.3:

3.

17. The preheating device according to claim 15, characterized in that, The ratio of the diameter of the circular baffle (22) to the inner diameter of the outer shell (2) is 0.5:2.

6.

18. The preheating device according to claim 15, characterized in that, The ratio of the spacing between each of the circular baffles (22) to the internal height of the outer shell (2) is 0.5:

3.

19. The preheating device according to claim 1, characterized in that, The ratio of the difference between the outer diameter and the inner diameter of the spiral baffle (21) to the inner diameter of the outer shell (2) is 1:(1.5-3); the ratio of the pitch of the spiral baffle (21) to the internal height of the outer shell (2) is (0.2-1.5):3; the ratio of the thickness of the spiral baffle (21) to the inner diameter of the coal-water slurry pipe (10) is 2:

50. The outer shell (2) is also provided with an annular baffle (23); the central axis of the annular baffle (23) coincides with the central axis of the outer shell (2); the width of the annular baffle (23) is 1: (2-6) to the inner diameter of the outer shell (2); the thickness of the annular baffle (23) is 2: 50 to the inner diameter of the coal-water slurry pipe (10).

20. The preheating device according to claim 19, characterized in that, The ratio of the difference between the outer diameter and the inner diameter of the spiral baffle (21) to the inner diameter of the outer shell (2) is 1.6:2.

6.

21. The preheating device according to claim 19, characterized in that, The ratio of the pitch of the spiral baffle (21) to the internal height of the outer shell (2) is 0.5:

3.

22. The preheating device according to claim 19, characterized in that, The width of the annular baffle (23) is 1:2.6 to the inner diameter of the outer shell (2).

23. The application of a preheating device as described in any one of claims 1-22 in preheated hot coal slurry.

24. The application of the preheating device according to claim 23, characterized in that, The concentration of the coal-water slurry is 50%-70%, and the percentage is the ratio of the mass of coal in the coal-water slurry to the mass of the coal-water slurry. The viscosity of the coal-water slurry is 300-1300 mPa·s, and the viscosity is tested at the feed temperature of the coal-water slurry. The flow velocity of the coal-water slurry in the heat transfer enhancement tube (1) is 0.1-3 m / s; The preheating device uses steam preheating.

25. The application of the preheating device according to claim 24, characterized in that, The concentration of the coal-water slurry is 62%, which is the ratio of the mass of coal in the coal-water slurry to the mass of the coal-water slurry.

26. The application of the preheating device according to claim 24, characterized in that, The viscosity of the coal-water slurry is 600 mPa·s, and the viscosity is tested at the feed temperature of the coal-water slurry.

27. The application of the preheating device according to claim 24, characterized in that, The flow velocity of the coal-water slurry in the heat transfer enhancement tube (1) is 0.5 m / s.

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