Heat exchange tube and heat exchange device suitable for heat exchange between low-order pulverized coal and gas
By setting opposite heat exchange parts and dislocation fin structures on the inner wall of the heat exchange tube, combined with the temperature compensation tube and the dispersed cavity design, the problem of high heat exchange cost of low-order pulverized coal is solved, and a low-cost and efficient heating effect of pulverized coal is achieved.
Patent Information
- Application Number
- CN202422460164.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-10-11
AI Technical Summary
In existing heat exchangers, when low-order pulverized coal is heat exchanged with gas, the fin processing is complex and costly, resulting in low heat absorption efficiency of pulverized coal and unable to reach a predetermined temperature in an oxygen-free environment.
A heat exchange tube and device are designed, and heat exchange parts that are protruding and distributed oppositely on the inner wall of the tube cavity. Combined with the outer fins and a dislocation heat exchange tube structure, the flue gas intake pipe is equipped with a dispersed cavity and a baffle to evenly distribute the flue gas, and the temperature compensation pipe increases the flue gas temperature to ensure uniform heating.
The processing and procurement costs are reduced, while maintaining the heat exchange effect. The flue gas forms turbulent flow in the tube cavity, heats the pulverized coal evenly, and utilizes the flue gas heat energy to the maximum extent.
Smart Images
Figure CN223243378U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of low-temperature dry distillation of pulverized coal, in particular to a heat exchange tube and a heat exchange device suitable for heat exchange between low-grade pulverized coal and gas. Background Art
[0002] During low-temperature carbonization, low-grade pulverized coal needs to be upgraded in an oxygen-free environment at 400-450°C. However, the gaps between particles in the pulverized coal are small, and the flue gas cannot flow smoothly in the pulverized coal pile, making it impossible to exchange heat by directly sending the flue gas into the furnace. Therefore, a heat exchanger is needed to exchange heat between the flue gas and the pulverized coal.
[0003] To improve heat absorption efficiency, conventional heat exchangers typically incorporate internal fins within the tubes, covering the entire inner cavity. The flue gas used for heat exchange typically has a temperature of 600-700°C. While this structure achieves effective heat transfer, the heat absorption efficiency of pulverized coal is significantly lower than that of the tubes. Therefore, while the tubes quickly reach the desired temperature, the pulverized coal will not reach 400-450°C. Furthermore, the fins within the tubes are complex and expensive to manufacture, leading to high procurement costs. Utility Model Content
[0004] The technical problem to be solved by the utility model is to provide a heat exchange tube and a heat exchange device which are low in cost and do not affect the heat exchange effect of the pulverized coal and are suitable for heat exchange between low-grade pulverized coal and gas.
[0005] In order to solve the above problems, the utility model provides a heat exchange tube and a heat exchange device suitable for heat exchange between low-grade pulverized coal and gas. The heat exchange tube suitable for heat exchange between low-grade pulverized coal and gas includes a heat exchange tube body having a tube cavity for flue gas flow and multiple heat exchange parts arranged in the tube cavity. The heat exchange parts are arranged on the inner wall of the tube cavity and protrude toward the center of the tube cavity. The upper and lower adjacent heat exchange parts are distributed oppositely in the tube cavity.
[0006] Furthermore, the arc length of the heat exchange portion is smaller than the circular circumference of the lumen.
[0007] Furthermore, the outer wall of the heat exchange tube body is provided with external fins.
[0008] Furthermore, the heat exchange tube body includes an upper tube body, a staggered tube body and a lower tube body, the upper tube body and the lower tube body are connected by the staggered tube body, the staggered tube body is arranged obliquely, and a heat exchange part is provided in the upper tube body and the lower tube body.
[0009] Furthermore, the heat exchange portion includes a plurality of inner fins arranged in a matrix.
[0010] In order to solve the above problems, the utility model provides a heat exchange device, which includes a flue gas outlet pipe, a flue gas inlet pipe and a heat exchange tube as described above. The flue gas outlet pipe and the flue gas inlet pipe are connected by multiple rows of heat exchange tubes, and the flue gas inlet pipe is located below the flue gas outlet pipe.
[0011] Furthermore, the flue gas inlet pipe has a first air inlet cavity and a first dispersion cavity installed on and connected to the first air inlet cavity. The connection position between the first air inlet cavity and the first dispersion cavity is located in the middle of the first air inlet pipe. A first baffle for dispersing the flue gas is provided in the first dispersion cavity. The first baffle is located at the position where the first air inlet cavity and the first dispersion cavity are connected.
[0012] Furthermore, it also includes at least one temperature compensating tube, which is located between the flue gas outlet pipe and the flue gas inlet pipe, and is connected to the flue gas outlet pipe by multiple rows of heat exchange tubes, and is connected to the flue gas inlet pipe by multiple rows of heat exchange tubes; when there are more than two temperature compensating tubes, the temperature compensating tubes are connected to each other by multiple rows of heat exchange tubes; a heating device is provided on the temperature compensating tube, and the heating device is used to increase the temperature of the flue gas in the temperature compensating tube.
[0013] Furthermore, the temperature compensating tube has a second air inlet cavity and a second dispersion cavity installed on and connected to the second air inlet cavity. The connection position between the second air inlet cavity and the second dispersion cavity is located in the middle of the second air inlet pipe. A second baffle for dispersing the smoke is provided in the second dispersion cavity. The second baffle is located at the position where the second air inlet cavity and the second dispersion cavity are connected.
[0014] Furthermore, the left and right rows of heat exchange tubes that are adjacent to each other in the width direction of the flue gas outlet pipe and located at the same horizontal position are staggered in the length direction of the flue gas outlet pipe.
[0015] The utility model is suitable for heat exchange tubes and heat exchange devices for heat exchange between low-grade pulverized coal and gas, and the heat exchange parts are retained to ensure the heat exchange effect; at the same time, the upper and lower adjacent heat exchange parts are arranged in opposition, which can reduce the processing volume, reduce the processing cost and thus reduce the procurement cost; and the oppositely arranged heat exchange parts can also make the flue gas turbulent and flow in an S shape in the tube cavity, ensuring that the flue gas can evenly heat the heat exchange tube, thereby maximizing the use of the heat energy of the flue gas. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a structural schematic diagram of the heat exchange device of the present utility model.
[0017] Figure 2 It is a schematic diagram of the flue gas flow in the heat exchange device of the present utility model.
[0018] Figure 3 This is a distribution diagram of the heat exchange device of the utility model in the furnace body.
[0019] Figure 4 It is a side view of the heat exchange device of the utility model installed in the furnace body.
[0020] Figure 5 It is the distribution diagram of the heat exchange tubes between the flue gas outlet pipe and the temperature compensation tube.
[0021] Figure 6 It is a structural diagram of the heat exchange tube.
[0022] Figure 7 It is a schematic diagram of the internal structure of the heat exchange tube.
[0023] Figure 8 It is a cross-sectional view of AA.
[0024] The meanings of the reference numerals in the accompanying drawings are:
[0025] Flue gas outlet pipe 1, flue gas inlet pipe 2, first air inlet pipe body 21, first dispersion pipe body 22, first baffle 23, first air inlet cavity 201, first dispersion cavity 202, temperature compensation tube 3, second air inlet pipe body 31, second dispersion pipe body 32, second baffle 33, second air inlet cavity 301, second dispersion cavity 302, heat exchange tube 4, heat exchange tube body 41, upper tube body 411, staggered tube body 412, lower tube body 413, heat exchange part 42, inner fin 421, outer fin 43, furnace body 5. DETAILED DESCRIPTION
[0026] The present invention will be further described below with reference to the accompanying drawings.
[0027] like Figures 1 to 4 As shown, a preferred embodiment of the heat exchange device of the present invention includes a flue gas outlet pipe 1, a flue gas inlet pipe 2, a temperature compensation pipe 3, and heat exchange pipes 4. The flue gas inlet pipe 2 is located below the flue gas outlet pipe 1, and the temperature compensation pipe 3 is located between the flue gas outlet pipe 1 and the flue gas inlet pipe 2. The temperature compensation pipe 3 is connected to the flue gas outlet pipe 1 via four rows of heat exchange pipes 4; the temperature compensation pipe 3 is connected to the temperature compensation pipe 3 via four rows of heat exchange pipes 4; and the temperature compensation pipe 3 is connected to the flue gas inlet pipe 2 via four rows of heat exchange pipes 4. The heat exchange pipes 4 in each row are distributed at the same intervals. The flue gas inlet pipe 2 is used to introduce high-temperature flue gas and deliver it to the heat exchange tube 4; the heat exchange tube 4 is used to exchange heat with the pulverized coal. The temperature compensating tube 3 is equipped with a heating device 6, which is a burner and is used to increase the temperature of the flue gas within the temperature compensating tube 3. The flue gas outlet pipe 1 is used to collect the flue gas after all heat exchanges have been completed and discharge the flue gas out of the furnace body 5. Multiple heat exchange devices are arranged side by side within a furnace body 5.
[0028] For ease of understanding, the heat exchange tube 4 between the temperature compensation tube 3 and the flue gas outlet pipe 1 is defined as the upper heat exchange tube 4, the heat exchange tube 4 between the temperature compensation tube 3 and the temperature compensation tube 3 is defined as the middle heat exchange tube 4, and the heat exchange tube 4 between the temperature compensation tube 3 and the flue gas inlet pipe 2 is defined as the lower heat exchange tube 4. Figure 5 As shown, the left and right rows of heat exchange tubes 4 at the same horizontal position are staggered in the length direction of the flue gas outlet pipe 1, that is, the left and right adjacent rows of heat exchange tubes 4 at the same layer are staggered in the length direction of the flue gas outlet pipe 1; specifically, the first heat exchange tube 4 in one row is located between the first heat exchange tube 4 and the second heat exchange tube 4 in an adjacent row, or the first heat exchange tube 4 in one row is ahead of the first heat exchange tube 4 in an adjacent row, and so on.
[0029] The flue gas inlet pipe 2 includes a first inlet pipe body 21 and a first dispersion pipe body 22. The first dispersion pipe body 22 is mounted on the first inlet pipe body 21. The first inlet pipe body 21 has a first inlet cavity 201, and the first dispersion pipe body 22 has a first dispersion cavity 202. The heat exchange pipe 4 is mounted on the first dispersion pipe body 22 and communicates with the first dispersion cavity 202. Through holes are provided on both the first inlet pipe body 21 and the first dispersion pipe body 22. The through holes on the first inlet cavity 201 are aligned with the through holes on the first dispersion cavity 202, so that the first inlet cavity 201 and the first dispersion cavity 202 are communicated. In this way, flue gas can enter the first dispersion cavity 202 from the first inlet cavity 201 and then enter the heat exchange pipe 4 for heat exchange. Both ends of the first inlet cavity 201 are air inlets, which increase the air intake speed. The through hole of the first air inlet cavity 201 is located in the middle of the first air inlet cavity 201, and the through hole of the first dispersion cavity 202 is located in the middle of the first dispersion cavity 202. A first baffle 23 for dispersing the flue gas is also provided in the first dispersion cavity 202. The position of the first baffle 23 is located in the middle of the first dispersion cavity 202, so that the first baffle 23 corresponds to the position of the through hole, so that the flue gas is first dispersed by the first baffle 23 after entering the first dispersion cavity 202 and then enters the heat exchange tube 4. The flue gas is distributed as evenly as possible before entering the heat exchange tube 4 connected to the first dispersion cavity 202, thereby ensuring that the temperature of the heat exchange tube 4 connected to the first dispersion cavity 202 remains consistent. In other embodiments, the flue gas inlet pipe 2 can also be a larger pipe, with two opposing partitions arranged inside the pipe to divide the internal space of the pipe into a first air inlet cavity 201 and a first dispersion cavity 202. The first air inlet cavity 201 is located below the partition, and the first dispersion cavity 202 is located above the partition. A gap is left between the partitions to ensure that the first air inlet cavity 201 and the first dispersion cavity 202 are connected.
[0030] The temperature compensating tube 3 includes a second air intake pipe body 31 and a second dispersion pipe body 32. The second dispersion pipe body 32 is mounted on the second air intake pipe body 31. The second air intake pipe body 31 has a second air intake cavity 301, and the second dispersion pipe body 32 has a second dispersion cavity 302. The heat exchange pipe 4 above the temperature compensating tube 3 is mounted on the second dispersion pipe body 32 and communicates with the second dispersion cavity 302. The heat exchange pipe 4 below the temperature compensating tube 3 is mounted on the second air intake pipe body 31 and communicates with the second air intake cavity 301. Both the second air intake pipe body 31 and the second dispersion pipe body 32 are provided with through holes. The through holes in the second air intake cavity 301 are aligned with the through holes in the second dispersion cavity 302, so that the second air intake cavity 301 and the second dispersion cavity 302 are connected. In this way, the flue gas in the heat exchange pipe 4 below the temperature compensating tube 3 can enter the second dispersion cavity 302 from the second air intake cavity 301, and then enter the heat exchange pipe 4 above the temperature compensating tube 3 for heat exchange. Both ends of the second air inlet cavity 301 are air inlets, which increase the air intake speed. The through hole of the second air inlet cavity 301 is located in the middle of the second air inlet cavity 301, and the through hole of the second dispersion cavity 302 is located in the middle of the second dispersion cavity 302. A second baffle 33 for dispersing the flue gas is also provided in the second dispersion cavity 302. The position of the second baffle 33 is located in the middle of the second dispersion cavity 302, so that the second baffle 33 corresponds to the position of the through hole, so that the flue gas is first dispersed by the second baffle 33 after entering the second dispersion cavity 302 and then enters the heat exchange tube 4. The flue gas is distributed as evenly as possible before entering the heat exchange tube 4 connected to the second dispersion cavity 302, thereby ensuring that the temperature of the heat exchange tube 4 connected to the second dispersion cavity 302 remains consistent. The temperature compensation tube 3 is different according to the height of the position, and the temperature of the flue gas heated by the heating device 6 is different to ensure the heat exchange requirements. In other embodiments, the temperature compensation tube 3 can also be a larger tube, with two opposing partitions arranged inside the tube to divide the internal space of the tube into a second air inlet cavity 301 and a second dispersion cavity 302. The second air inlet cavity 301 is located below the partition plate, and the second dispersion cavity 302 is located above the partition plate. A gap is left between the partition plates to ensure that the second air inlet cavity 301 and the second dispersion cavity 302 are connected.
[0031] like Figures 6 to 8As shown, the heat exchange tube 4 includes a heat exchange tube body 41 and multiple heat exchange sections 42 provided on the heat exchange tube body 41. The heat exchange tube body 41 has a tube lumen for flue gas flow. The heat exchange sections 42 are provided on the inner wall of the tube lumen and protrude toward the center of the tube lumen to increase the heat exchange area and ensure heat absorption efficiency. The upper and lower adjacent heat exchange sections 42 are arranged opposite each other within the tube lumen, that is, the heat exchange sections 42 are arranged alternately on the left and right sides within the tube lumen. The outer wall of the heat exchange tube body 41 is provided with external fins 43. The external fins 43 are used to increase the heat exchange area, that is, to increase the contact area between the heat exchange tube body 41 and the pulverized coal. Typically, four external fins 43 are provided. Excessive external fins 43 are not recommended, as they can easily cause the pulverized coal to accumulate and eventually agglomerate. This is to prevent the pulverized coal from agglomerating.
[0032] The arc length of the heat exchange portion 42 is less than the circular circumference of the tube lumen, typically set to half the circumference of the center of the tube lumen. This ensures a certain heat exchange effect while also allowing the flue gas to form turbulent flow within the tube lumen. Turbulent flow prevents the same portion of flue gas from always contacting the heat exchange tube 4. This prevents the temperature of flue gas near the center of the tube lumen from being higher than that of flue gas near the inner wall of the tube lumen. The temperature of flue gas at the same height is essentially the same, allowing the thermal energy of all the flue gas to be utilized. The heat exchange portion 42 includes multiple inner fins 421 arranged in a matrix, utilizing a conventional fin structure. This eliminates the need for new processing techniques and reduces processing costs.
[0033] The heat exchange tube body 41 includes an upper tube body 411, a staggered tube body 412 and a lower tube body 413. A heat exchange part 42 is provided in the upper tube body 411 and the lower tube body 413. The upper tube body 411 and the lower tube body 413 are connected by the staggered tube body 412. The staggered tube body 412 is arranged at an angle so that the upper tube body 411 and the lower tube body 413 are staggered, thereby realizing the staggered direction of the heat exchange tube 4 in the vertical direction.
[0034] By staggering the heat exchange tubes 4 vertically, and staggering adjacent rows of heat exchange tubes 4, the pulverized coal is evenly heated and, during the drop process, becomes fluffy and less likely to clump. Compared to a conventional matrix arrangement with no staggering, the staggered arrangement of heat exchange tubes 4 in this application reduces the number of heat exchange tubes 4 by half while still achieving the same heat exchange effect and further increasing the fluffiness of the pulverized coal.
[0035] During use, the pulverized coal first passes through the upper heat exchange tubes 4 for initial heating, then enters the middle heat exchange tubes 4 for secondary heating, and finally enters the lower heat exchange tubes 4 for final heating. The staggered arrangement of the heat exchange tubes 4 makes the pulverized coal fluffy and less likely to clump during its fall. The heat exchange tubes 4 retain heat exchange sections 42, ensuring effective heat exchange. The opposing arrangement of the upper and lower adjacent heat exchange sections 42 reduces processing effort, lowers processing costs, and thus reduces procurement costs. Furthermore, the opposing heat exchange sections 42 create turbulent flue gas flow, forming an S-shaped flow within the tube lumen, ensuring that the flue gas evenly heats the heat exchange tubes 4 and maximizing the utilization of the flue gas's thermal energy.
[0036] The above is only an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure made using the contents of the description and drawings of the present invention, directly or indirectly used in other related technical fields, is also within the patent protection scope of the present invention.
Claims
1. A heat exchange tube suitable for heat exchange between low-grade pulverized coal and gas, characterized by: It includes a heat exchange tube body with a tube cavity for flue gas flow and multiple heat exchange parts arranged in the tube cavity. The heat exchange parts are arranged on the inner wall of the tube cavity and protrude toward the center of the tube cavity. The upper and lower adjacent heat exchange parts are oppositely distributed in the tube cavity.
2. The heat exchange tube suitable for heat exchange between low-grade pulverized coal and gas according to claim 1, characterized in that: The arc length of the heat exchange portion is smaller than the circular circumference of the tube cavity.
3. The heat exchange tube suitable for heat exchange between low-grade pulverized coal and gas according to claim 1, characterized in that: The outer wall of the heat exchange tube body is provided with external fins.
4. The heat exchange tube suitable for heat exchange between low-grade pulverized coal and gas according to claim 1, characterized in that: The heat exchange tube body includes an upper tube body, a staggered tube body and a lower tube body, the upper tube body and the lower tube body are connected by the staggered tube body, the staggered tube body is arranged obliquely, and a heat exchange part is provided in the upper tube body and the lower tube body.
5. The heat exchange tube suitable for heat exchange between low-grade pulverized coal and gas according to claim 1, characterized in that: The heat exchange portion includes a plurality of inner fins arranged in a matrix.
6. A heat exchange device, characterized in that: It comprises a flue gas outlet pipe, a flue gas inlet pipe and a heat exchange pipe according to any one of claims 1 to 4, wherein the flue gas outlet pipe and the flue gas inlet pipe are connected through multiple rows of heat exchange pipes, and the flue gas inlet pipe is located below the flue gas outlet pipe.
7. The heat exchange device according to claim 6, characterized in that: The flue gas inlet pipe has a first air inlet cavity and a first dispersion cavity installed on and connected to the first air inlet cavity. The communication position between the first air inlet cavity and the first dispersion cavity is located in the middle of the first air inlet pipe. A first baffle for dispersing the flue gas is provided in the first dispersion cavity. The first baffle is located at the position where the first air inlet cavity and the first dispersion cavity are connected.
8. The heat exchange device according to claim 6, wherein: It also includes at least one temperature compensating tube, which is located between the flue gas outlet pipe and the flue gas inlet pipe. The temperature compensating tube and the flue gas outlet pipe are connected via multiple rows of heat exchange tubes, and the temperature compensating tube and the flue gas inlet pipe are connected via multiple rows of heat exchange tubes. When there are more than two temperature compensating tubes, the temperature compensating tubes are connected via multiple rows of heat exchange tubes. A heating device is provided on the temperature compensating tube, which is used to increase the temperature of the flue gas in the temperature compensating tube.
9. The heat exchange device according to claim 8, characterized in that: The temperature compensating tube has a second air inlet cavity and a second dispersion cavity installed on and connected to the second air inlet cavity. The connection position between the second air inlet cavity and the second dispersion cavity is located in the middle of the second air inlet pipe. A second baffle for dispersing smoke is provided in the second dispersion cavity. The second baffle is located at the position where the second air inlet cavity and the second dispersion cavity are connected.
10. The heat exchange device according to claim 6, wherein: The left and right rows of heat exchange tubes located at the same horizontal position and adjacent to each other in the width direction of the flue gas outlet pipe are staggered in the length direction of the flue gas outlet pipe.