High-low temperature asymmetric runner gas preheater
Through the asymmetric pure countercurrent heat transfer design and high-efficiency HP heat exchange pipe structure of high and low temperature asymmetric runner gas preheater, the low-temperature corrosion and ash accumulation problems of traditional gas preheaters are solved, and the gas preheating effect and heat exchange are improved Efficiency extends the life of the equipment.
Patent Information
- Application Number
- CN202410218188.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-27
- Publication Date
- 2024-12-06
AI Technical Summary
The presence of H2S components in blast furnace gas by traditional gas preheaters leads to low temperature corrosion and ash accumulation, and there is no adaptive change in the heat exchange area, resulting in low heat exchange performance and poor gas preheating effect.
Design a high and low temperature asymmetric runner gas preheater, adopting asymmetric pure countercurrent heat transfer design and high-efficiency HP heat exchange tube, combining elliptical straight tube and elliptical torsion tube structure, the flue gas flows along the length of the tube bundle, forming a spiral disturbance flow, improve heat exchange efficiency, and optimize structures through modular assembly and self-support design.
It improves the gas preheating effect, reduces the possibility of ash accumulation and scaling of flue gas, extends the service life of the preheater, reduces the consumption of metal materials in the low-temperature section, and improves the heat exchange efficiency by 50-100%.
Smart Images
Figure CN119085360A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of coal gas preheating, and in particular to a high-low temperature asymmetric flow channel coal gas preheater. Background Art
[0002] The gas preheater is an energy-saving device used to increase the temperature of coal gas. By preheating coal gas, fuel consumption can be reduced and combustion efficiency can be improved. During the operation of the gas preheater, due to the inevitable presence of H2S components in blast furnace gas, the components after combustion will combine with H2O to form dilute sulfuric acid. The wall temperature of the heat exchange element at the gas inlet section is lower than the acid dew point, resulting in low-temperature corrosion and ash accumulation. The low-temperature section of the traditional gas preheater is divided into two units, upper and lower, with a transverse partition in the middle, which leads to the accumulation of corrosion condensates, exacerbating corrosion and scaling; at the same time, due to load fluctuations and furnace changes, the flue gas and coal gas flow rates are reduced, and the heat exchange area of the traditional gas preheater has no ability to adapt to changes, resulting in a further decrease in the exhaust gas temperature, exacerbating the low-temperature corrosion problem, resulting in a decrease in heat exchange performance, and poor gas preheating effect. Summary of the invention
[0003] In view of the problem in the prior art that low heat exchange performance leads to poor gas preheating effect, the present invention provides a high and low temperature asymmetric flow channel gas preheater, which can improve the heat exchange performance, thereby achieving better gas preheating effect.
[0004] To achieve the above object, the present invention can be carried out by adopting the following technical solutions:
[0005] The present invention provides a high-low temperature asymmetric flow channel coal gas preheater, which comprises:
[0006] A shell, the top of which is respectively provided with a gas inlet and a gas outlet, a high-temperature section preheating component and a low-temperature section preheating component are arranged inside the shell, the high-temperature section preheating component is arranged below the gas outlet, the low-temperature section preheating component is arranged below the gas inlet, the high-temperature section preheating component is connected with the low-temperature section preheating component via a bottom channel, a side wall of the shell is respectively provided with a smoke inlet and a smoke outlet, the smoke inlet is arranged on one side of the shell near the high-temperature section preheating component, and the smoke outlet is arranged on one side of the shell near the low-temperature section preheating component;
[0007] A plurality of heat exchange tubes, which are arranged inside the shell;
[0008] Among them, the internal spaces of several of the heat exchange tubes form a gas flow channel, and the external gaps between several of the heat exchange tubes form a smoke flow channel. The gas in the gas flow channel is preheated by the high-temperature section preheating component and the low-temperature section preheating component, and the gas in the gas flow channel undergoes thermal interaction with the smoke in the smoke flow channel.
[0009] The high and low temperature asymmetric flow channel gas preheater as described above further includes a tube sheet, which is respectively arranged on the upper and lower sides of the high temperature section preheating component and the low temperature section preheating component and forms a closed space with the inner wall of the shell, and a plurality of the heat exchange tubes pass through the tube sheet and are welded to the tube sheet.
[0010] As in the above-mentioned high and low temperature asymmetric flow channel gas preheater, further, a ash cleaning port is opened on the side wall of the bottom of the shell.
[0011] As in the above-mentioned high and low temperature asymmetric flow channel gas preheater, further, the gas inlet, the gas outlet, the smoke inlet and the smoke outlet are all provided with reducing interfaces.
[0012] As in the above-mentioned high-low temperature asymmetric flow channel gas preheater, further, the flattening rate of the heat exchange tube arranged at the high-temperature section preheating component is greater than the flattening rate of the heat exchange tube arranged at the low-temperature section preheating component, the materials of the heat exchange tubes at the high-temperature section preheating component and the low-temperature section preheating component are different, and the low-temperature section preheating component adopts stainless steel material with stronger corrosion resistance.
[0013] As in the above-mentioned high and low temperature asymmetric flow channel gas preheater, further, the heat exchange tube is a high-efficiency HP heat exchange tube.
[0014] As in the above-mentioned high and low temperature asymmetric flow channel gas preheater, further, one end of the high-efficiency HP heat exchange tube arranged at the high temperature section preheating component is an elliptical straight tube, and the other end is an elliptical twisted tube, and the short axis of the elliptical straight tube is the windward surface.
[0015] As in the above-mentioned high-low temperature asymmetric flow channel coal gas preheater, further, one end of the high-efficiency HP heat exchange tube arranged at the low-temperature section preheating component is a straight round tube, and the other end is an elliptical twisted tube.
[0016] As in the above-mentioned high and low temperature asymmetric flow channel gas preheater, further, the plurality of heat exchange tubes are modularly arranged, and the plurality of heat exchange tubes are arranged in a rectangular distribution manner.
[0017] As in the above-mentioned high and low temperature asymmetric flow channel coal gas preheater, further, a plurality of the heat exchange tubes form a heat exchange tube bundle, and the heat exchange tube bundle realizes a self-supporting function by supporting each other through the raised sections between adjacent heat exchange tubes.
[0018] Compared with the prior art, the present invention has the following beneficial effects:
[0019] 1. The coal gas and flue gas adopt an asymmetric pure countercurrent heat flow design, which makes the heat exchange end difference of the preheater small and the flue gas inlet temperature is as close as possible to the coal gas outlet temperature. The heat exchange tube adopts high-efficiency HP heat exchange tube, and the fluid inside and outside the tube can form a strong spiral turbulence, destroying the boundary layer close to the heat exchange wall, which not only improves the heat exchange efficiency by 50-100%, but also reduces the possibility of flue gas ash accumulation and scaling;
[0020] 2. The heat exchange tube bundle can be self-supporting, and there is no baffle design on the shell side. The flue gas flows along the length of the tube bundle, and the flow resistance is small. At the high-temperature flue gas inlet, the heat exchange tube is set as an elliptical straight tube section to further reduce the flue gas resistance at the inlet;
[0021] 3. The high and low temperature asymmetric flow channel is used to optimize the pipe layout design, so that the wall temperature of the heat exchange tube in the low temperature section is close to the high temperature flue gas side, which increases the wall temperature of the heat exchange surface, improves the low temperature corrosion problem from the process mechanism, extends the service life of the preheater, and reduces the consumption of expensive metal materials in the low temperature section;
[0022] 4. Modular assembly is adopted to facilitate equipment manufacturing, transportation, installation and maintenance. The compact structure is conducive to on-site installation and hoisting operations, and the installation period is short. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0024] Figure 1 It is a structural front view of a preheater according to an embodiment of the present invention;
[0025] Figure 2 A top view of the structure of a preheater according to an embodiment of the present invention;
[0026] Figure 3 This is a schematic diagram of the structure of a high-efficiency HP heat exchange tube disposed at a high-temperature section preheating assembly according to an embodiment of the present invention;
[0027] Figure 4 This is a schematic diagram of the structure of a high-efficiency HP heat exchange tube disposed at a low-temperature section preheating assembly according to an embodiment of the present invention;
[0028] Among them, 1. gas inlet; 2. gas outlet; 3. flue gas inlet; 4. flue gas outlet; 5. high temperature section preheating assembly; 6. low temperature section preheating assembly; 7. shell; 8. ash cleaning port; 9. heat exchange tube; 10. tube sheet; 11. elliptical straight tube; 12 elliptical twisted tube; 13 straight round tube. DETAILED DESCRIPTION
[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0030] Example:
[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations of the embodiments of the present invention are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0032] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.
[0033] In the description of the present invention, "multiple" means at least two, such as two, three, etc., unless otherwise clearly defined. In addition, unless otherwise clearly defined and defined, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.
[0035] The present invention provides a high-low temperature asymmetric flow channel coal gas preheater, comprising a shell 7 and a plurality of heat exchange tubes 9, wherein a coal gas inlet 1 and a coal gas outlet 2 are respectively arranged on the top of the shell 7, a high temperature section preheating component 5 and a low temperature section preheating component 6 are arranged inside the shell 7, the high temperature section preheating component 5 is arranged below the coal gas outlet 2, the low temperature section preheating component 6 is arranged below the coal gas inlet 1, the high temperature section preheating component 5 and the low temperature section preheating component 6 are connected via a bottom channel, a smoke inlet 3 and a smoke outlet 4 are respectively opened on the side wall of the shell 7, the smoke inlet 3 is opened on one side of the shell 7 close to the high temperature section preheating component 5, the smoke outlet 4 is opened on one side of the shell 7 close to the low temperature section preheating component 6, and a plurality of heat exchange tubes 9 are arranged inside the shell 7; wherein the internal space of the plurality of heat exchange tubes 9 forms a coal gas flow channel, the external gaps between the plurality of heat exchange tubes 9 form a smoke flow channel, the coal gas in the coal gas flow channel is preheated by the high temperature section preheating component 5 and the low temperature section preheating component 6, and the coal gas in the coal gas flow channel is thermally interacted with the smoke in the smoke flow channel.
[0036] Specifically, when the preheater is in operation, the coal gas enters the heat exchange tube 9 at the low temperature section preheating assembly 6 from the coal gas inlet 1 at the top of the shell 7, flows from top to bottom to the bottom along the heat exchange tube 9 for initial temperature increase, then enters the heat exchange tube 9 in the high temperature section preheating assembly 5 through the bottom channel of the low temperature section preheating assembly 6, then flows from bottom to top for secondary temperature increase to the required temperature, and finally leaves from the coal gas outlet 2, and the entire coal gas flow trajectory is U-shaped; at the same time, the flue gas enters the high temperature section preheating assembly 5 from the flue gas inlet 3 and flows from top to bottom, then enters the low temperature section preheating assembly 6 through the bottom of the high temperature section preheating assembly 5 and turns to flow upward, and finally leaves from the flue gas outlet 4, and the entire flue gas flow trajectory is also U-shaped. In this way, a U-shaped pure countercurrent flow space of coal gas and flue gas is formed, so that the heat exchange end difference of the preheater is small, the temperature of the flue gas temperature inlet 3 and the coal gas outlet 2 are as close as possible, the heat exchange temperature difference is maximized, the heat exchange performance is improved, and the coal gas preheating effect is better.
[0037] As an optional implementation, in some embodiments, a tube sheet 10 is further included, and the tube sheet 10 is respectively arranged on the upper and lower sides of the high-temperature section preheating assembly 5 and the low-temperature section preheating assembly 6 and forms a closed space with the inner wall of the shell, and a plurality of heat exchange tubes 9 pass through the tube sheet 10 and are welded on the tube sheet 10. Among them, the tube sheet 10 is installed on the upper and lower sides of the high-temperature section preheating assembly 5 and the low-temperature section preheating assembly 6, so as to form a closed space with the inner wall of the shell, which can further improve the air tightness and heat preservation of the place.
[0038] As an optional implementation, in some embodiments, a cleaning port 8 is provided on the side wall of the bottom of the housing 7. The cleaning port 8 is provided to facilitate cleaning and discharging of dust or other particles accumulated inside the housing 7.
[0039] As an optional implementation, in some embodiments, the gas inlet 1, the gas outlet 2, the smoke inlet 3 and the smoke outlet 4 are all provided with reducers. The reducers can connect pipes of different diameters. Therefore, installing the reducers facilitates the gas inlet 1, the gas outlet 2, the smoke inlet 3 and the smoke outlet 4 of the housing 7 to better connect different gas pipes and smoke pipes, thereby improving adaptability.
[0040] As an optional implementation, in some embodiments, the flattening rate of the heat exchange tube 9 arranged at the high-temperature preheating component 5 is greater than the flattening rate of the heat exchange tube 9 arranged at the low-temperature preheating component 6. In this way, the flow channel space of the coal gas and the flue gas inside and outside the heat exchange tube 9 can be effectively regulated, and the flow rate of the coal gas inside the low-temperature preheating component 6 can be further reduced, so that the temperature of the coal gas and the flue gas can be fully heat exchanged, thereby improving the heat exchange performance of the preheater. In addition, the materials of the heat exchange tubes 9 at the high-temperature preheating component 5 and the low-temperature preheating component 6 are different, and the low-temperature preheating component 6 can be made of stainless steel with stronger corrosion resistance.
[0041] As an optional implementation, in some embodiments, the heat exchange tube 9 is a high-efficiency HP heat exchange tube. Among them, the high-efficiency HP heat exchange tube has a special spiral structure, and the fluid inside and outside the tube can form a strong spiral turbulence, which enhances the disturbance of the boundary layer of the fluid inside and outside the tube, destroys the boundary layer close to the heat exchange wall, thus enhancing the heat transfer effect, ensuring the gas flow rate while reducing the pressure drop, and improving the heat exchange efficiency by 50-100%, while reducing the possibility of flue gas ash accumulation and scaling, and improving the ability to resist ash accumulation.
[0042] In the above embodiment, further, one end of the high-efficiency HP heat exchange tube arranged at the high-temperature preheating component 5 is an elliptical straight tube 11, and the other end is an elliptical twisted tube 12, and the short axis of the elliptical straight tube 11 is the windward surface; one end of the high-efficiency HP heat exchange tube arranged at the low-temperature preheating component 6 is a straight round tube 13, and the other end is an elliptical twisted tube 12. Among them, the straight round tube 13 arranged at the upper part of the low-temperature preheating component 6 can reduce the flow rate and heat transfer coefficient of the low-temperature coal gas in the heat exchange tube 9, and at the same time increase the flow rate and heat transfer coefficient of the high-temperature flue gas outside the heat exchange tube 9, so that the wall temperature of the heat exchange tube 9 is closer to the high-temperature flue gas outside the heat exchange tube 9, thereby ensuring that the wall temperature of the heat exchange tube 9 at the inlet is higher than the acid dew point temperature, thereby avoiding the heat exchange tube 9 at the inlet from being corroded by low temperature, thereby extending the service life of the preheater and reducing the consumption of expensive metal materials at the low-temperature preheating component 6; and at the inlet of the high-temperature section of the flue gas, the volume flow of the flue gas is the largest, and the elliptical straight tube 11 can make the flue gas enter the flow channel more smoothly and minimize the body resistance.
[0043] As an optional implementation, in some embodiments, a plurality of heat exchange tubes 9 are modularly arranged, and a plurality of heat exchange tubes 9 are arranged in a rectangular distribution. The modular assembly is adopted to facilitate the manufacture, transportation, installation, and maintenance of the heat exchange tubes 9. The compact structure is conducive to on-site installation and hoisting operations, and the installation period is short.
[0044] As an optional implementation, in some embodiments, a plurality of heat exchange tubes 9 form a heat exchange tube bundle, and the heat exchange tube bundle supports each other through the convex sections between adjacent heat exchange tubes 9 to achieve a self-supporting function. The heat exchange tube bundle relies on the convex sections between adjacent heat exchange tubes 9 to support and block each other at multiple points, forming a grid-like integrated structure, thereby achieving a self-supporting effect. At the same time, this design makes the shell side without baffles, which can reduce pressure drop, reduce scaling, improve heat transfer efficiency, simplify the structure and facilitate maintenance.
[0045] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0046] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made based on the essence of the content of the present invention should be included in the protection scope of the present invention.
Claims
1. A high and low temperature asymmetric flow channel gas preheater, characterized in that: include: A shell, the top of which is respectively provided with a gas inlet and a gas outlet, a high-temperature section preheating component and a low-temperature section preheating component are arranged inside the shell, the high-temperature section preheating component is arranged below the gas outlet, the low-temperature section preheating component is arranged below the gas inlet, the high-temperature section preheating component is connected with the low-temperature section preheating component via a bottom channel, a side wall of the shell is respectively provided with a smoke inlet and a smoke outlet, the smoke inlet is arranged on one side of the shell near the high-temperature section preheating component, and the smoke outlet is arranged on one side of the shell near the low-temperature section preheating component; A plurality of heat exchange tubes, which are arranged inside the shell; Among them, the internal spaces of several of the heat exchange tubes form a gas flow channel, and the external gaps between several of the heat exchange tubes form a smoke flow channel. The gas in the gas flow channel is preheated by the high-temperature section preheating component and the low-temperature section preheating component, and the gas in the gas flow channel undergoes thermal interaction with the smoke in the smoke flow channel.
2. The high and low temperature asymmetric flow channel gas preheater according to claim 1 is characterized in that: It also includes tube sheets, which are respectively arranged on the upper and lower sides of the high-temperature section preheating assembly and the low-temperature section preheating assembly and form a closed space with the inner wall of the shell. Several heat exchange tubes pass through the tube sheets and are welded to the tube sheets.
3. The high and low temperature asymmetric flow channel gas preheater according to claim 1, characterized in that: A dust cleaning port is provided on the side wall of the bottom of the shell.
4. The high and low temperature asymmetric flow channel gas preheater according to claim 1, characterized in that: The gas inlet, the gas outlet, the smoke inlet and the smoke outlet are all provided with reducing interfaces.
5. The high and low temperature asymmetric flow channel gas preheater according to claim 1, characterized in that: The flattening rate of the heat exchange tube arranged at the high-temperature section preheating component is greater than the flattening rate of the heat exchange tube arranged at the low-temperature section preheating component. The materials of the heat exchange tubes at the high-temperature section preheating component and the low-temperature section preheating component are different. The low-temperature section preheating component adopts stainless steel material with stronger corrosion resistance.
6. The high and low temperature asymmetric flow channel gas preheater according to claim 1, characterized in that: The heat exchange tubes are high-efficiency HP heat exchange tubes.
7. The high and low temperature asymmetric flow channel gas preheater according to claim 6, characterized in that: One end of the high-efficiency HP heat exchange tube arranged at the high-temperature section preheating component is an elliptical straight tube, and the other end is an elliptical twisted tube, and the short axis of the elliptical straight tube is the windward surface.
8. The high and low temperature asymmetric flow channel gas preheater according to claim 6, characterized in that: One end of the high-efficiency HP heat exchange tube arranged at the low-temperature section preheating component is a straight round tube, and the other end is an elliptical twisted tube.
9. The high and low temperature asymmetric flow channel gas preheater according to claim 1, characterized in that: The heat exchange tubes are modularly configured, and are arranged in a rectangular distribution.
10. The high and low temperature asymmetric flow channel gas preheater according to claim 1, characterized in that: A plurality of the heat exchange tubes form a heat exchange tube bundle, and the heat exchange tube bundle supports each other through the raised sections between adjacent heat exchange tubes to achieve a self-supporting function.