A riser heat exchanger

Abstract

This invention relates to a riser heat exchanger, comprising: a cylindrical body; heat exchange coils arranged spirally along the extension direction of the cylindrical body channel; an arc-shaped plate support assembly, including a first arc-shaped plate and a second arc-shaped plate both arranged spirally along the extension direction of the channel, the cross-sections of the first and second arc-shaped plates being C-shaped, the orientation of the C-shaped openings of the first and second arc-shaped plates being opposite to the orientation of the C-shaped openings of the second arc-shaped plate, and both being disposed together in the installation gap of the heat exchange coils, simultaneously supporting two adjacent layers of the heat exchange coils; and an oleophobic coating applied to the side of the heat exchange coils and the arc-shaped plate support assembly facing the center of the cylindrical body, the internal space enclosed by the oleophobic coating forming a heat exchange channel for the raw coal gas to pass through. This riser heat exchanger enhances the turbulence of the raw coal gas flow, resulting in good heat exchange performance, effectively eliminating vibration problems caused by water flow impact, and reducing temperature difference stress caused by temperature fluctuations, thereby extending its service life.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology, and more particularly to a riser heat exchanger. Background Technology

[0002] Coking coal is heated and dry-distilled in a coke oven in the absence of air to produce coke, while simultaneously generating a large amount of volatile raw coal gas. The sensible heat carried out by the 950–1050℃ red-hot coke exiting the coke oven carbonization chamber accounts for 37% of the coke oven's total heat output; the sensible heat carried out by the 550–850℃ raw coal gas accounts for 36%; the heat carried out by the 180–230℃ flue gas accounts for 17%; and heat loss from the oven surface accounts for 10%. For the sensible heat carried out by coke, mature and reliable dry quenching devices exist for recovery and power generation. However, for the sensible heat carried out by the raw coal gas, traditional coking processes involve spraying large amounts of circulating ammonia water at 70–85℃ to cool the high-temperature raw coal gas. After lowering the temperature, the gas enters a primary cooler, where circulating water and low-temperature cooling water further reduce the temperature to around 21℃. Subsequent raw coal gas purification recovers byproducts such as tar, crude benzene, and sulfur. However, the sensible heat of the high-temperature raw coal gas is entirely wasted. Currently, many companies use riser pipe waste heat recovery devices to recover the sensible heat of raw coal gas, reduce energy consumption, and improve their competitiveness in the market.

[0003] The main technical challenges of waste heat recovery from riser pipes are as follows:

[0004] (1) It cannot be tar or graphite: When the temperature of the inner wall of the riser is below 450℃, the coal tar will condense, and when the temperature is above 800℃, the tar will carbonize. The tar is easy to deposit on the inner wall of the riser. When the riser cover is opened, black smoke and yellow smoke will be emitted, causing environmental pollution.

[0005] (2) Absolutely no water leakage: The riser pipe is installed directly on the coke oven carbonization chamber. If the heat exchanger leaks water, it can easily enter the carbonization chamber, which will damage the coke oven masonry and even destroy the furnace body.

[0006] (3) High material requirements: The raw coal gas contains a large amount of corrosive gases such as tar, ammonia, and hydrogen sulfide, which are corrosive at high temperatures; the waste heat recovery temperature of the raw coal gas generally fluctuates periodically between 550-850℃, with a large range of variation. Under special circumstances, the internal temperature of the riser pipe can reach more than 1100℃, and oxidizing and reducing atmospheres alternate. Therefore, the material selection requirements are high.

[0007] (4) Structural limitations: The new riser heat exchanger cannot change the original connection design, and the space for structural adjustment is limited.

[0008] (5) Poor on-site environment: The coke oven top is exposed to high temperatures, dust and corrosive gases, and the on-site environment is harsh.

[0009] The use of novel riser heat exchangers to replace traditional riser tubes for recovering the sensible heat of raw coal gas has been applied in some coke ovens in China, but many problems still exist. Currently, the main structural forms of riser heat exchangers are: external coil type, internal coil type, insertion type, and water jacket type. The heat exchange medium is mainly water. The specific problems of various riser heat exchanger structures are as follows:

[0010] External coil riser pipes typically have an inner cylinder made of rolled and welded steel plate approximately 10mm thick, with fins welded to the inner wall. The outer coil is spirally wound around the outer wall of the cylinder, and solid heat-conducting material is used to fill the spaces between the coils. External coil riser pipes can withstand high pressures and are suitable for producing medium-pressure steam with high quality; due to their thinner inner wall, they are relatively simple to manufacture.

[0011] The main disadvantages of external coil riser pipes are as follows: 1. The external coil is in line contact with the inner cylinder, which is a secondary indirect heat exchange, resulting in poor heat exchange efficiency. It is necessary to add heat-conducting material between the coils and fins to the inner cylinder to enhance heat exchange. 2. To improve heat exchange efficiency, the inner cylinder uses thin steel plates with poor rigidity. Prolonged high temperatures can easily lead to creep, deformation, or even perforation, directly affecting safe operation and causing the external coil to separate from the outer wall of the inner cylinder. Simultaneously, the heat-conducting material will also degenerate under prolonged high temperatures, gradually separating from the inner cylinder, posing a risk of localized overheating and gradually reducing steam production. Thickening the steel plate to prevent deformation not only increases manufacturing costs but also reduces heat exchange efficiency. 3. The bottom fins absorb radiant heat from the furnace and will thin and deform under large temperature fluctuations and corrosive gas impacts. Tar easily accumulates on the inner wall fins, making cleaning difficult and affecting the cleaning of the riser pipe base. Furthermore, fins cannot be used in coke ovens that employ mechanical cleaning of the riser pipes.

[0012] The internal coil type riser pipe structure is similar to the external coil type, with the coil inserted inside the riser pipe for direct heat exchange with the raw coal gas. Its advantage is good heat exchange efficiency. However, its disadvantages include insufficient rigidity due to the direct installation of the coil inside the riser pipe. Even with high-grade stainless steel, the internal coil is prone to metal creep under conditions of significant temperature fluctuations and alternating redox atmospheres, leading to pipe deformation and breakage. This can allow water to directly enter the carbonization chamber, damaging the furnace and posing a significant safety hazard. Furthermore, the internal coil is prone to tar and carbon buildup, resulting in reduced heat transfer and difficulty in cleaning.

[0013] Insertion-type riser heat exchange elements have a U-shaped tube structure and are inserted into the riser tube. The heat exchange elements are made of high-grade heat-resistant stainless steel. Their advantages include no need to replace the original riser tube, easy installation, and the lowest manufacturing and installation costs. However, their disadvantages are similar to those of internal coil riser tubes: they are prone to metal creep causing deformation and leakage, surface coking is easy, and their service life is short.

[0014] The inner cylinder of the water-jacketed riser pipe is made of thick-walled seamless pipe, and the outer side is made of water jacket layer. The jacket is equipped with an expansion joint to eliminate the thermal expansion caused by the temperature difference between the inner and outer cylinders. However, the water-jacketed type also has some disadvantages: the pressure bearing capacity of the jacket type is not as good as that of the coil type, and it can generally only produce low-pressure steam of 0.6 to 2 MPa; tar is prone to accumulate on the inner wall of the riser pipe, which affects the steam production rate.

[0015] To address this, Chinese utility model patent application number CN202021989954.7 (CN213327448U) discloses a novel riser pipe waste heat recovery structure, comprising a riser pipe wall, an insulation layer fixedly connected to the inner surface of the riser pipe wall, a heat-extracting pipe assembly fixedly installed on the side of the insulation layer away from the riser pipe wall, a ceramic layer fixedly connected to the side of the heat-extracting pipe assembly away from the insulation layer, a lower connecting pipe fixedly connected to the bottom of the riser pipe wall, and a lower ring plate fixedly connected to the end of the lower connecting pipe away from the riser pipe wall. In this patent, the heat-extracting pipe assembly of the riser pipe waste heat recovery structure has a corrugated profile, creating local vortices in the boundary region of the raw coal gas flow, significantly preventing coking. The outer surface of the heat-extracting pipe assembly is covered with a ceramic layer of special refractory material, avoiding direct contact between the raw coal gas and the metal of the riser pipe heat-extracting pipe assembly, thus eliminating corrosion conditions.

[0016] However, the riser pipe waste heat recovery structure in the aforementioned patent has certain shortcomings. The upper and lower layers of the heat extraction pipe assembly are basically arranged in close contact. During long-term operation, due to factors such as temperature difference, temperature fluctuation, and vibration caused by water flow impact, the heat extraction pipe assembly is prone to deformation, and even coil breakage may occur. On the other hand, the fact that the upper and lower layers of the heat extraction pipe assembly are basically arranged in close contact makes it impossible to install corresponding temperature measuring devices in the gaps between the pipe components, thus preventing accurate temperature measurement of the raw coal gas inside the riser pipe.

[0017] Therefore, existing riser heat exchangers still need further improvement. Summary of the Invention

[0018] The first technical problem to be solved by the present invention is to provide a riser heat exchanger that has good heat exchange effect, can effectively eliminate the vibration problem caused by water flow impact and reduce the temperature difference stress caused by temperature fluctuation, thereby extending its service life, in light of the current state of the prior art.

[0019] The second technical problem to be solved by the present invention is to provide a riser heat exchanger that is convenient for setting up a temperature measuring device, in view of the current state of the prior art.

[0020] The technical solution adopted by this invention to solve the first technical problem is: a riser heat exchanger, comprising:

[0021] The cylindrical body has a hollow interior forming a channel;

[0022] The heat exchange coil is installed in the channel of the cylinder and is arranged in a spiral shape along the extension direction of the channel. An installation gap is reserved between any two adjacent layers of the heat exchange coil.

[0023] The arc plate support assembly includes a first arc plate and a second arc plate, both arranged spirally along the extension direction of the channel. The cross-sections of the first arc plate and the second arc plate are both C-shaped. The orientation of the C-shaped opening of the first arc plate is opposite to that of the C-shaped opening of the second arc plate. Both are arranged together in the installation gap of the heat exchange coil and simultaneously support the two adjacent layers of the heat exchange coil.

[0024] An oleophobic coating is applied to the side of the heat exchange coil and the arc plate support assembly facing the center of the cylinder. The internal space enclosed by the oleophobic coating forms a heat exchange channel for the raw coal gas to pass through.

[0025] As an improvement, the first arc-shaped plate has a first sidewall facing the opening and a second sidewall facing away from the opening, and the second arc-shaped plate has a third sidewall facing the opening and a fourth sidewall facing away from the opening. The second sidewall of the first arc-shaped plate and the fourth sidewall of the second arc-shaped plate are arranged opposite each other. The second arc-shaped plate is located on the side of the first arc-shaped plate away from the cylinder body. The side edge of the third sidewall of the second arc-shaped plate is in contact with the tube wall of the heat exchange coil, so that the cross-section of the oleophobic coating on the tube wall of the heat exchange coil and the third sidewall of the second arc-shaped plate is wavy along the extension direction of the cylinder body. Utilizing the arc-shaped structural characteristics of the second arc-shaped plate, the oleophobic coating on the heat exchange coil and the second arc-shaped plate has a wavy structure. This changes the flow state of the raw gas in the heat exchange channel from laminar to turbulent, greatly increasing the heat transfer coefficient and improving the heat transfer effect.

[0026] To achieve a reliable connection between the heat exchange coil and the arc plate support assembly, and to securely fix the connection between them, the first arc plate has a first side and a second side, which are respectively welded to the tube walls of two adjacent layers of coils on the heat exchange coil. The second arc plate has a third side and a fourth side, which are respectively welded to the tube walls of two adjacent layers of coils on the heat exchange coil.

[0027] To further ensure the support strength of the arc-shaped plate support assembly for the heat exchange coil, the second sidewall of the first arc-shaped plate abuts against the fourth sidewall of the second arc-shaped plate. It is conceivable that when the support strength of the first and second arc-shaped plates is sufficient, a certain gap can be reserved between them.

[0028] To further improve the heat exchange effect, the radius of curvature of the second arc-shaped plate is basically the same as that of the heat exchange coil, so that the cross-section of the oleophobic coating along the extension direction of the cylinder is sinusoidal. The cross-sectional shape of the heat exchanger inner wall (i.e., the oleophobic coating) is a sinusoidal structure with no sharp dead zones. This not only prevents tar from accumulating in the dead zones, but also generates turbulence when the raw gas flows, reducing the temperature difference between the inner wall of the riser heat exchanger and the center of the raw gas, thereby significantly improving the heat exchange effect.

[0029] As an improvement, the thickness of the oleophobic coating is 0.01 mm to 5 mm. Preferably, the thickness of the oleophobic coating is 0.1 mm to 1 mm. The relatively small thickness of the oleophobic coating is equivalent to the heat exchange coil being in direct contact with the raw coal gas, resulting in lower metal thermal resistance and better heat exchange effect compared to external coil heat exchangers.

[0030] To reduce heat loss through outward transfer, an insulation layer is also provided on the inner wall of the cylinder, and the heat exchange coil and arc plate support assembly abut against the insulation layer on the side facing the cylinder.

[0031] The technical solution adopted by the present invention to solve the second technical problem is as follows: it further includes a temperature measuring hole set at the location corresponding to the installation gap of the heat exchange coil and extending from the cylinder to the heat exchange flow channel.

[0032] To prevent the cylinder from breaking due to thermal stress, an expansion joint is also provided on the cylinder.

[0033] To prevent pressure changes caused by temperature rise inside the interlayer between the arc plate support assembly and the heat exchange coil, there is an interlayer gap between the arc plate support assembly and the heat exchange coil.

[0034] It also includes a detection vent hole extending from the cylinder to the interlayer gap.

[0035] Compared with the prior art, the advantages of the present invention are:

[0036] The riser heat exchanger of this invention incorporates an arc-shaped plate support assembly in the installation gap between adjacent layers of the heat exchange coil. Due to the inherent structural characteristics of this arc-shaped plate support assembly (using two back-to-back arc-shaped plates that simultaneously support adjacent layers of the heat exchange coil), it possesses a degree of flexibility, allowing for axial expansion and contraction. This effectively eliminates vibrations caused by water flow impact, reduces thermal stress caused by temperature fluctuations, and prevents deformation and damage to the heat exchange coil, thereby effectively extending its service life. Furthermore, the arc-shaped plates connected to the heat exchange tubes provide a fin-like effect during heat exchange, enhancing heat transfer and simultaneously generating strong turbulence in the flow of raw coal gas, thus improving the overall heat exchange efficiency of the riser. The oleophobic coating inside the heat exchanger is applied to the side of the heat exchange coil and the arc plate support assembly facing the center of the cylinder. This is equivalent to the heat exchange coil directly exchanging heat with the raw coal gas. Compared with the existing external coil heat exchanger, it has a lower metal thermal resistance. Compared with the internal coil heat exchanger and the insertion heat exchanger, its contact area with the raw coal gas is smaller (only the side of the heat exchange coil facing the center of the cylinder exchanges heat with the raw coal gas). The huge temperature fluctuations of the raw coal gas have a smaller impact on the heat exchange coil. At the same time, the oleophobic coating can both repel oil and self-clean, avoid tar coking and adhesion, reduce the thermal resistance of dirt, and prevent the heat exchange coil from directly contacting the raw coal gas. This prevents the tar, ammonia, hydrogen sulfide and other substances in the raw coal gas from corroding the heat exchange coil and prevents the alternating oxidizing and reducing atmospheres from damaging the strength of the heat exchange coil. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the riser heat exchanger according to an embodiment of the present invention;

[0038] Figure 2 for Figure 1 Enlarged view of point A in the middle. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0040] The specification and claims of this invention use terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," to describe various exemplary structural parts and elements of the invention. However, these terms are used herein merely for ease of explanation and are determined based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this invention can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be considered as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0041] See Figure 1 and Figure 2A riser heat exchanger includes a cylinder 10, an insulation layer 13, a heat exchange coil 20, an arc plate support assembly 30, and an oleophobic coating 40.

[0042] The cylindrical body 10 is vertically oriented and has a hollow interior forming a channel 11. This channel 11 houses the aforementioned insulation layer 13, heat exchange coil 20, arc-shaped plate support assembly 30, and oleophobic coating 40. In this embodiment, the cylindrical body 10 is made of metal and has at least one expansion joint 12 along its axial direction to prevent damage due to thermal stress. The channel 11 of the cylindrical body 10 has two opposing ports in the vertical direction.

[0043] The heat exchange coil 20 is disposed inside the cylinder 10 and arranged spirally along the extension direction of the channel 11. Figure 1 As can be seen, the axial length of the spiral heat exchange coil 20 in this embodiment is basically the same as the length of the cylinder 10. The lower end of the heat exchange coil 20 protrudes beyond the bottom of the circumferential wall of the cylinder 10 as a water inlet 24, and the upper end of the heat exchange coil 20 also protrudes beyond the top of the circumferential wall of the cylinder 10 as a steam outlet 25. An installation gap 26 is reserved between any two adjacent layers on the spiral heat exchange coil 20, such as... Figure 2 The upper pipe fitting 21 and the lower pipe fitting 22 of the heat exchange coil 20 shown in the figure form an installation gap 26. From the overall structure of the heat exchange coil 20, the installation gaps 26 are of the same size and are connected in sequence, which also forms an installation gap 26 that is also arranged in a spiral shape.

[0044] The heat exchange coil 20 in this embodiment can be made of low-carbon carbon steel or heat-resistant steel, such as ferritic heat-resistant steel, pearlitic heat-resistant steel, martensitic heat-resistant steel, or austenitic heat-resistant steel. The heat exchange coil 20 uses thick-walled, high-pressure resistant pipes, which have high rigidity and strength, preventing metal creep caused by large temperature fluctuations during operation, and can produce medium-pressure steam above 2.5 MPa.

[0045] The arc-shaped plate support assembly 30 is also spiral-shaped and is correspondingly disposed in the spiral mounting gap 26 of the heat exchange coil 20 to provide overall support for the heat exchange coil 20. Specifically, the arc-shaped plate support assembly 30 includes a first arc-shaped plate 31 and a second arc-shaped plate 32, wherein both the first arc-shaped plate 31 and the second arc-shaped plate 32 are spirally arranged along the extension direction of the channel 11. The cross-sections of the first arc-shaped plate 31 and the second arc-shaped plate 32 are both C-shaped. The first arc-shaped plate 31 has a first sidewall 311 facing the opening and a second sidewall 312 away from the opening, and also has opposing first sidewalls 313 and second sidewalls 314. The second arc-shaped plate 32 has a third sidewall 321 facing the opening and a fourth sidewall 322 away from the opening, and also has opposing third sidewalls 323 and fourth sidewalls 324. In this embodiment, the first arc-shaped plate 31 and the second arc-shaped plate 32 have basically the same structure and dimensions. The second arc-shaped plate 32 is located on the side of the first arc-shaped plate 31 away from the cylinder 10. Furthermore, the second sidewall 312 of the first arc-shaped plate 31 and the fourth sidewall 322 of the second arc-shaped plate 32 are opposite to each other. That is, the first sidewall 311 of the first arc-shaped plate 31 faces outward along the radial direction of the cylinder 10, the second sidewall 312 faces inward along the radial direction of the cylinder 10, the third sidewall 321 of the second arc-shaped plate 32 faces inward along the radial direction of the cylinder 10, and the fourth sidewall 322 faces outward along the radial direction of the cylinder 10. More specifically, the first side 313 and the second side 314 of the first arc-shaped plate 31 are respectively welded to the tube walls of two adjacent layers of coils on the heat exchange coil 20, and the third side 323 and the fourth side 324 of the second arc-shaped plate 32 are also respectively welded to the tube walls of two adjacent layers of coils on the heat exchange coil 20. Figure 2 As shown, the first side 313 of the first arc-shaped plate 31 and the third side 323 of the second arc-shaped plate 32 are located on the same side, supporting the bottom of the upper pipe fitting 21. The second side 314 of the first arc-shaped plate 31 and the fourth side 324 of the second arc-shaped plate 32 are located on the same side, supporting the top of the lower pipe fitting 22. To further ensure the support strength of the arc-shaped plate support assembly 30 for the heat exchange coil 20, in this embodiment, the second side wall 312 of the first arc-shaped plate 31 abuts against the fourth side wall 322 of the second arc-shaped plate 32.

[0046] The oleophobic coating 40 can be a ceramic coating, specifically applied to the third sidewall 321 of the second arc-shaped plate 32 and the side of the heat exchange coil 20 facing the center of the cylinder 10. The internal space enclosed by the oleophobic coating 40 forms a heat exchange channel 41 through which raw coal gas passes. The lower end of the heat exchange channel 41 forms the raw coal gas inlet 42, and the upper end forms the raw coal gas outlet 43, through which the raw coal gas flows out after heat exchange. The raw coal gas inlet 42 is connected to the coke oven body via a flange, and the raw coal gas outlet 43 is connected to the downstream raw coal gas pipeline via a flange.

[0047] See Figure 2The side edge of the third sidewall 321 of the second arc-shaped plate 32 smoothly transitions into the tube wall of the heat exchange coil 20, resulting in a wavy cross-section of the oleophobic coating 40 applied to the tube wall of the heat exchange coil 20 and the third sidewall 321 of the second arc-shaped plate 32 along the extension direction of the cylinder 10. Specifically, the radius of curvature of the second arc-shaped plate 32 is basically the same as the radius of curvature of the heat exchange coil 20, thus the cross-section of the oleophobic coating 40 along the extension direction of the cylinder 10 is sinusoidal. The portion of the oleophobic coating 40 on the third sidewall 321 of the second arc-shaped plate 32 and the portion of the oleophobic coating 40 on the tube wall of the heat exchange coil 20 correspond to the peaks and troughs of the sine wave, respectively. The cross-sectional shape of the heat exchanger inner wall (i.e., the oleophobic coating 40) is a sinusoidal structure with no sharp-angle dead zones, preventing tar accumulation in the dead zones. On the other hand, through flow field simulation, compared with the planar structure of the inner wall of a conventional water-jacketed heat exchanger, the sinusoidal structure inside the heat exchanger of this invention causes the flow pattern of raw coal gas to change from laminar to turbulent when it passes through, which greatly improves its heat transfer coefficient. Since the coil can withstand higher pressure than the jacket, the steam pressure produced by the heat exchanger in this embodiment is higher than that of the water-jacketed type.

[0048] The thickness of the oleophobic coating 40 in this embodiment is 0.01 mm to 5 mm, preferably 0.1 mm to 1 mm. The oleophobic coating 40 can be a ceramic coating. The relatively small thickness of the oleophobic coating 40 is equivalent to the heat exchange coil 20 being in direct contact with the raw coal gas. Compared with an external coil heat exchanger, the metal thermal resistance is lower and the heat exchange effect is better.

[0049] The insulation layer 13 is affixed to the inner wall of the cylinder 10, specifically wrapping around the heat exchange coil 20 and the arc plate support assembly 30 to reduce heat loss through outward transfer. The side of the heat exchange coil 20 facing the cylinder 10 is in contact with the insulation layer 13, and the first sidewall 311 of the first arc plate 31 of the arc plate support assembly 30 is in contact with the insulation layer 13.

[0050] There is a gap 23 between the first arc-shaped plate 31, the second arc-shaped plate 32, and the tube wall of the heat exchange coil 20. To prevent pressure changes caused by temperature rise inside the gap 23, a venting hole 52 is provided on the riser heat exchanger, extending from the cylinder 10 to the gap 23. Figure 1 As shown, there are two detection vent holes 52, located near the upper and lower ends of the cylinder 10, respectively. These detection vent holes 52 serve a leak detection function. When the second arc-shaped plate 32 is damaged, or the weld between the second arc-shaped plate 32 and the heat exchange coil 20 is damaged, raw coal gas leaks into the installation gap 26. Yellow raw coal gas smoke can be observed through the detection vent holes 52, allowing for timely detection during manhole inspections. When the heat exchange coil 20 ruptures, water vapor leaks into the installation gap 26 and is discharged through the vent holes 52, also allowing for timely detection during manual inspections.

[0051] The riser heat exchanger also has temperature measuring holes 51a and 51b at positions corresponding to the installation gap 26 of the heat exchange coil 20. These temperature measuring holes 51a and 51b extend from the outer wall of the cylinder 10 (passing sequentially through the insulation layer 13, the second arc-shaped plate 32, and the first arc-shaped plate 31) into the heat exchange flow channel 41 within the oleophobic coating 40. The large spacing between adjacent sections of the heat exchange coil 20, i.e., the existence of the installation gap 26, allows the riser heat exchanger to easily have temperature measuring holes 51a and 51b at any desired location and to install temperature measuring devices.

[0052] See Figure 1 The riser heat exchanger has multiple temperature measuring holes 51a and 51b along its length for installing online temperature sensing elements to accurately measure the temperature of the raw coal gas inside the heat exchanger. The multiple temperature measuring holes 51a and 51b are a central temperature measuring hole 51a and a wall temperature measuring hole 51b, respectively. The central temperature measuring hole 51a is located near the central axis of the heat exchanger and is used to measure the temperature of the raw coal gas at the center of the riser heat exchanger. The wall temperature measuring hole 51b is located near the inner wall of the heat exchanger and is used to measure the temperature of the raw coal gas near the wall. This allows for real-time monitoring to ensure that the temperature of the raw coal gas at the wall is not below 450℃, preventing the accumulation of tar and other components. Simultaneously, the temperature difference between the central temperature measuring hole 51a and the wall temperature measuring hole 51b can be used to monitor the turbulence effect of the raw coal gas inside the riser; a smaller temperature difference between the center and the wall indicates a better turbulence effect.

[0053] The advantages of the riser tube heat exchanger in this embodiment are as follows:

[0054] 1. The arc plate support assembly 30 is welded to the heat exchange coils 20 above and below it, connecting the entire heat exchange coil 20 into a whole. Due to the flexibility and buffering properties of the arc plate structure, the entire heat exchange coil 20 can be stabilized, which can greatly reduce the vibration caused by the impact of water flow on the heat exchange coil 20 and prevent the heat exchange coil 20 from being damaged.

[0055] 2. The riser heat exchanger is equipped with an arc-shaped plate support assembly 30 in the installation gap 26 between two adjacent layers of the heat exchange coil 20. Due to the structural characteristics of the arc-shaped plate support assembly 30 (using two arc-shaped plates set in opposite directions to support two adjacent layers of the heat exchange coil 20), it has a certain degree of flexibility (similar to the function of the metal expansion joint 12). It can expand and contract in the axial direction, which can effectively compensate for the thermal expansion difference caused by the different metal wall temperatures in different parts of the heat exchanger, reduce the thermal stress of the heat exchanger, avoid heat exchanger damage caused by deformation due to temperature difference and temperature fluctuation, and prevent water leakage from the riser heat exchanger into the carbonization chamber and damage to the coke oven wall.

[0056] 3. The arc-shaped plate support assembly 30 welded to the heat exchange tube (especially the second arc-shaped plate 32 for coating with oleophobic coating 40) has a fin-like effect of enhanced heat transfer during the heat exchange process, which improves the overall heat exchange efficiency of the riser tube. The oleophobic coating 40 inside the heat exchanger is applied to the side of the heat exchange coil 20 and the arc plate support assembly 30 facing the center of the cylinder 10. This is equivalent to the heat exchange coil 20 directly exchanging heat with the raw coal gas. Compared with the external coil heat exchanger in the prior art, it has a lower metal thermal resistance. Compared with the internal coil heat exchanger and the insertion heat exchanger, its contact area with the raw coal gas is smaller (only the side of the heat exchange coil 20 facing the center of the cylinder 10 exchanges heat with the raw coal gas). The huge temperature fluctuations of the raw coal gas have a smaller impact on the heat exchange coil 20. At the same time, the oleophobic coating 40 can both repel oil and self-clean, avoid tar coking and adhesion, reduce the thermal resistance of dirt, and prevent the heat exchange coil 20 from directly contacting the raw coal gas. This prevents the tar, ammonia, hydrogen sulfide and other substances in the raw coal gas from corroding the heat exchange coil 20 and prevents the alternating oxidizing and reducing atmospheres from damaging the strength of the heat exchange coil 20.

[0057] 4. By utilizing the arc-shaped structure of the second arc plate 32 and the tube wall of the heat exchange coil 20, the cross-section of the oleophobic coating 40 coated on the heat exchange coil 20 and the second arc plate 32 is wavy. This changes the flow state of the raw coal gas in the heat exchange channel 41 from laminar to turbulent, greatly increasing the heat transfer coefficient and improving the heat transfer effect. In particular, the sinusoidal oleophobic coating 40 has no sharp dead zones, which can effectively prevent tar from accumulating in the dead zones.

[0058] 5. Under the support of the arc plate support assembly 30, there is a relatively large gap between adjacent sections of the heat exchange coil 20 (i.e., installation gap 26), so that the temperature measuring device can be easily installed at any required location.

Claims

1. A riser heat exchanger, comprising: a cylinder (10) having a channel (11) formed in the inside thereof; a heat exchange coil (20) disposed in the channel (11) of the cylinder (10) and arranged in a spiral along the extension direction of the channel (11), and having an installation gap (26) reserved between any two adjacent layers of the heat exchange coil (20); characterized in that it further comprises: an arc plate support assembly (30) comprising a first arc plate (31) and a second arc plate (32) both arranged in a spiral along the extension direction of the channel (11), the cross section of the first arc plate (31) and the cross section of the second arc plate (32) both being C-shaped, the opening direction of the C-shaped opening of the first arc plate (31) being opposite to the opening direction of the C-shaped opening of the second arc plate (32), and both being disposed in the installation gap (26) of the heat exchange coil (20) and supporting the two adjacent layers of the heat exchange coil (20) at the same time; and an oleophobic coating (40) coated on the side of the heat exchange coil (20) and the arc plate support assembly (30) corresponding to the center of the cylinder (10), the internal space surrounded by the oleophobic coating (40) constituting a heat exchange flow channel (41) for passing raw coal gas. The first arc plate (31) has a first side wall (311) facing the opening and a second side wall (312) away from the opening, the second arc plate (32) has a third side wall (321) facing the opening and a fourth side wall (322) away from the opening, the second side wall (312) of the first arc plate (31) is disposed opposite to the fourth side wall (322) of the second arc plate (32), the second arc plate (32) is located on the side of the first arc plate (31) away from the cylinder (10), and the side edge of the third side wall (321) of the second arc plate (32) is in contact with the tube wall of the heat exchange coil (20), so that the oleophobic coating (40) coated on the tube wall of the heat exchange coil (20) and the third side wall (321) of the second arc plate (32) is in a wavy shape in the cross section along the extension direction of the cylinder (10). The first arc plate (31) has opposite first and second side edges (313, 314) respectively welded on the tube walls of the two adjacent layers of the heat exchange coil (20), and the second arc plate (32) has opposite third and fourth side edges (323, 324) respectively welded on the tube walls of the two adjacent layers of the heat exchange coil (20). The second side wall (312) of the first arc plate (31) is in abutment with the fourth side wall (322) of the second arc plate (32). The radius of curvature of the second arc plate (32) is substantially consistent with the radius of curvature of the heat exchange coil (20), so that the oleophobic coating (40) is in a sinusoidal shape in the cross section along the extension direction of the cylinder (10). The thickness of the oleophobic coating (40) is 0.01mm-5mm.

2. The riser heat exchanger of claim 1, wherein: ​ 3. The riser heat exchanger of claim 2, wherein: ​ 4. The riser heat exchanger of claim 3, wherein: ​ 5. The riser heat exchanger of claim 2, wherein: ​ 6. The riser heat exchanger of claim 1, wherein: ​ 7. The riser heat exchanger according to any one of claims 1 to 6, characterized in that Further comprising a heat insulation layer (13) arranged on the inner side wall of the cylinder (10), and the side of the heat exchange coil (20) and the arc plate support assembly (30) corresponding to the cylinder (10) is in contact with the heat insulation layer (13).

8. The riser heat exchanger of claim 7, wherein: Further comprising a temperature measuring hole (51a; 51b) penetrating through the cylinder (10) to the heat exchange flow channel (41) at a position corresponding to the installation gap (26) of the heat exchange coil (20).

9. The riser heat exchanger according to any one of claims 1 to 6, characterized in that: The cylinder (10) is further provided with an expansion joint (12).

10. The riser heat exchanger according to any one of claims 1 to 6, characterized in that: The arc plate support assembly (30) and the heat exchange coil (20) have a sandwich gap (23) therebetween. Further comprising a detection vent hole (52) penetrating through the cylinder (10) to the sandwich gap (23).

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