Novel washout-corrosion-resistant waste heat recovery heat exchanger

Abstract

The invention discloses a novel washout-corrosion-resistant waste heat recovery heat exchanger, and aims to solve the problem of washout corrosion of high-temperature and high-speed dust-containing flue gas to the heat exchanger. The heat exchanger comprises an upper shell, a lower shell, an integrated side plate box, heat exchange tubes, a discharge outlet, interception fins and the like. The heat exchange pipes are distributed in a multi-group array mode, and smoke impact is reduced through a smooth surface and a dense structure. The inverted-V-shaped intercepting fin plate is located above the discharge outlet and can intercept particles in the flue gas and recycle the particles through the negative pressure pipe. The whole device adopts a multi-channel structure to guarantee the flue gas treatment and flowing efficiency. The heat exchanger can reduce erosive wear, prolong the service life of equipment, stably recover waste heat and guarantee smooth proceeding of subsequent processes, is suitable for high-temperature dust-containing flue gas scenes such as an aluminum melting furnace, and is energy-saving and environment-friendly.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of heat exchangers, and particularly relates to a novel heat exchanger for recovering waste heat and resisting erosion and corrosion. BACKGROUND

[0002] The novel heat exchanger for recovering waste heat and resisting erosion and corrosion is widely applied to the waste heat recovery scene of high-temperature and high-speed dust-containing flue gas in the industrial field; the flue gas discharged by various industrial kilns and combustion equipment in the fields of thermal power generation, steel smelting and chemical production usually has the characteristics of high temperature, high-speed flow and carrying a large number of dust particles, for example, the flue gas discharged by a sintering machine in a steel sintering process and high-temperature dust-containing tail gas generated by a waste incinerator; the flue gas not only contains a large amount of recoverable heat energy, but also causes continuous erosion of the surface of the heat exchanger under the high-speed flow of the dust particles carried by the flue gas, and the acid gases (such as SO2 and HCl) in the flue gas form condensate under specific temperature conditions, further aggravating the corrosion damage of the equipment; the traditional heat exchanger usually faces problems of reduced heat exchange efficiency and short maintenance period under this kind of working condition, and a novel waste heat recovery equipment capable of resisting erosion and chemical corrosion is urgently needed.

[0003] Some devices in the prior art adopt a spiral finned tube structure and select ND steel (09CrCuSb) as the heat exchange tube material, aiming to improve the corrosion resistance of the material to cope with the corrosion problem of sulfur-containing flue gas; however, the technology mainly relies on a passive corrosion prevention strategy, and the spiral finned tube structure still has the following disadvantages in the high-temperature and high-speed dust-containing flue gas environment: first, the surface of the fin is easy to be worn due to the continuous impact of the dust particles, resulting in thinning or even breaking of the fin and weakening of the heat exchange area; second, although the ND steel has a certain corrosion resistance in concentrated sulfuric acid medium, it may still be corroded in a dilute acid environment or under high-temperature oxidation conditions, especially under the working condition of large flue gas temperature fluctuation, the passivation film on the surface of the material is easy to be damaged, and it is difficult to maintain stable protection performance for a long time; in addition, the patent does not propose an effective solution to the dust erosion caused by dust accumulation, and the dust accumulation may block the flow channel after long-term operation, further reducing the heat exchange efficiency.

[0004] In the prior art, the scouring and corrosion of high-temperature high-speed dust-containing flue gas on the heat exchanger mainly exhibit the synergistic effect of mechanical wear and chemical corrosion. On the one hand, the hard dust particles (such as SiO2, metal oxides, etc.) carried by the flue gas form a sandblasting-like effect under high-speed flow, continuously impact the surface of the heat exchanger, destroy the surface integrity of the material, and cause the metal matrix to be directly exposed to the corrosive medium. On the other hand, the acid gases (such as SO2, NOx, etc.) in the flue gas condense and form a liquid environment with strong corrosion in the low-temperature area of the heat exchanger, and an electrochemical reaction occurs with the metal surface, accelerating the corrosion loss of the material. The mutual promotion of scouring and corrosion significantly shortens the service life of the heat exchanger and increases the equipment maintenance and replacement costs. In addition, the structural design of the traditional heat exchanger often cannot balance the requirements of anti-scouring and anti-corrosion. For example, although the smooth tube structure can reduce dust accumulation, the heat exchange efficiency is low. When the finned tube or corrugated tube structure is used, the local scouring and wear are intensified due to the complex flow field. Therefore, the existing technology still has technical bottlenecks in material performance, structural design and protection mechanism in dealing with the scouring and corrosion of high-temperature high-speed dust-containing flue gas. Therefore, a new type of scouring and corrosion resistant waste heat recovery heat exchanger is proposed to solve the above problems. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art, and provides a new type of scouring and corrosion resistant waste heat recovery heat exchanger, which can solve the problem of equipment corrosion caused by continuous scouring of high-temperature high-speed dust-containing flue gas on the heat exchanger in the prior art, reduce the shortened service life and increased maintenance costs caused by scouring and wear, ensure stable waste heat recovery process, and improve the scouring and corrosion resistance of the equipment in high-temperature dust-containing flue gas environment.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a new type of scouring and corrosion resistant waste heat recovery heat exchanger, comprising an upper shell, a lower shell, an integrated side plate box and a heat exchange pipe, the lower shell is connected to the bottom end face of the upper shell and communicates with the inside thereof, the inside of the upper shell and the lower shell is welded with an integrated side plate box at the opposite inner side wall, the heat exchange pipe is integrally formed between the two integrated side plate boxes at the position close to the lower side in a multiple array distribution and parallel to each other, the smooth surface can disturb the flue gas flow to reduce the impact, and the dense array structure can disperse the flue gas impact force while realizing preheating and heat exchange, thereby reducing the scouring and wear. The discharge port is integrally formed on the two groups of integrated side plate boxes in a plurality of arrays and is parallel to each other, and the interception fin is connected between the two groups of integrated side plate boxes and is parallel to the heat exchange pipe, the interception fin is in an inverted V-shaped structure and is located directly above the discharge port, the inverted V-shaped structure can intercept particles in flue gas, and the discharge port can gather and absorb dust particles through negative pressure, thereby reducing the amount of particles entering the heat exchange pipe region below and reducing local erosion and wear; Preferably, airtight partitions for partitioning are embedded and mounted between the inner side of the interception fin and the inner side wall of the upper shell, the airtight partitions are located between the heat exchange pipe and the interception fin, and play a partitioning role, thereby avoiding the direct impact of intercepted particles or flue gas on the heat exchange pipe and further reducing erosion; Preferably, the upper shell is integrally connected with the heat exchange pipe coaxially at the front and rear outer walls of the upper shell and is in communication with the inner part of the interception fin of the front and rear sides of the upper shell, the heat exchange pipe is in communication with the heat exchange pipe through the interception fin, the upper shell is integrally connected with the negative pressure pipe coaxially at the front and rear outer walls of the upper shell and is in communication with the inner part of the interception fin of the front and rear sides of the upper shell, and the negative pressure pipe is in communication with the discharge port through the interception fin, thereby assisting the discharge port in absorbing and gathering particles through negative pressure, enhancing the particle recovery effect, and reducing secondary erosion; Preferably, the upper shell is integrally connected with the heat exchange pipe coaxially at the front and rear outer walls of the upper shell and is in communication with the inner part of the interception fin of the front and rear sides of the upper shell, the heat exchange pipe is in communication with the heat exchange pipe through the interception fin, the upper shell is integrally connected with the negative pressure pipe coaxially at the front and rear outer walls of the upper shell and is in communication with the inner part of the interception fin of the front and rear sides of the upper shell, and the negative pressure pipe is in communication with the discharge port through the interception fin, thereby assisting the discharge port in absorbing and gathering particles through negative pressure, enhancing the particle recovery effect, and reducing secondary erosion; Preferably, the upper shell is integrally connected with the heat exchange pipe coaxially at the front and rear outer walls of the upper shell and is in communication with the inner part of the interception fin of the front and rear sides of the upper shell, the heat exchange pipe is in communication with the heat exchange pipe through the interception fin, the upper shell is integrally connected with the negative pressure pipe coaxially at the front and rear outer walls of the upper shell and is in communication with the inner part of the interception fin of the front and rear sides of the upper shell, and the negative pressure pipe is in communication with the discharge port through the interception fin, thereby assisting the discharge port in absorbing and gathering particles through negative pressure, enhancing the particle recovery effect, and reducing secondary erosion; Preferably, the upper shell is integrally connected with the heat exchange pipe coaxially at the front and rear outer walls of the upper shell and is in communication with the inner part of the interception fin of the front and rear sides of the upper shell, the heat exchange pipe is in communication with the heat exchange pipe through the interception fin, the upper shell is integrally connected with the negative pressure pipe coaxially at the front and rear outer walls of the upper shell and is in communication with the inner part of the interception fin of the front and rear sides of the upper shell, and the negative pressure pipe is in communication with the discharge port through the interception fin, thereby assisting the discharge port in absorbing and gathering particles through negative pressure, enhancing the particle recovery effect, and reducing secondary erosion; Preferably, the diameter of the heat exchange pipe is equal to the diameter of the discharge port, and the inner length of the angle of the interception fin is equal to the diameter of the discharge port; the distance between the two groups of heat exchange pipes is equal to the diameter of the heat exchange pipe, and the distance between the two groups of discharge ports is greater than the diameter of the discharge port, so that reasonable size and spacing design can ensure heat exchange efficiency and reduce the problem of local erosion caused by structure.

[0007] Compared with the prior art, the present application has the following advantages: The new type of erosion corrosion resistant waste heat recovery heat exchanger, through the dense distribution of heat exchange pipes arranged in the middle section, the smooth surface can effectively disturb the flow state of the flue gas, reduce the direct impact of high temperature and high speed flue gas on the surface of the heat exchange pipe, reduce the erosion of the residual particles in the flue gas on the heat exchange pipe, and relieve the local wear problem caused by the surface form of the traditional heat exchange pipe from the structural design; at the same time, the dense distribution of the heat exchange pipe further disperses the impact force of the flue gas on the basis of realizing the preheating heat exchange function, and avoids the local area from being accelerated to be eroded due to the concentrated impact of the flue gas.

[0008] The new type of erosion corrosion resistant waste heat recovery heat exchanger, the setting of the inverted V-shaped interception fin plate can form effective interception of dust particles before the flue gas enters the middle section heat exchange area, reduce the number of particles entering the heat exchange pipe area; and the particle recovery holes at the inner two ends can absorb and accumulate dust particles by negative pressure, so that the intercepted particles can be discharged in time, avoiding the particles from being carried by the flue gas again after being accumulated on the fin plate to form secondary erosion, thereby significantly reducing the local erosion and wear of the heat exchange pipe and other parts of the equipment caused by the continuous impact of the particles.

[0009] The new type of erosion corrosion resistant waste heat recovery heat exchanger adopts a multi-channel structure, which can ensure the clear flow path and reasonable resistance of the flue gas in the equipment while reducing the particle erosion through the above measures, avoid the situation that the flue gas flows not smoothly or the local flow rate is too high due to improper structural design, ensure the flue gas treatment efficiency, and further reduce the erosion and wear caused by the intensification of flow field disorder, thereby prolonging the service life of the equipment and reducing the maintenance and replacement cost on the basis of improving the erosion corrosion resistance of the equipment.

[0010] The new type of erosion corrosion resistant waste heat recovery heat exchanger, through effective treatment of high temperature and high speed dust-containing flue gas, can ensure the stable progress of the waste heat recovery process while reducing erosion and wear to prolong the service life of the equipment, thereby continuously converting the heat energy in the flue gas into usable hot water, helping to meet the demand of related equipment for heat energy; at the same time, due to the long-term stable operation of the equipment, the flue gas emission temperature can be stably controlled in the appropriate range, providing favorable conditions for the smooth development of subsequent bag dust removal and other processes, and promoting the efficient use of energy and the realization of environmental protection goals as a whole. BRIEF DESCRIPTION OF DRAWINGS

[0011] The present application will be further described below in combination with the drawings and examples: Figure 1 is the left side view of the present application; Figure 2 is the right side view of the present application; Figure 3 is the top view of the present application; Figure 4 is a sectional view of A-A of the present application; Figure 5 is a sectional view of B-B of the present application; Figure 6 is an enlarged view of A of the present application.

[0012] Reference signs: 1, upper shell; 2, lower shell; 3, upper smoke outlet; 4, smoke inlet pipe; 5, side smoke inlet; 6, smoke outlet; 7, access hole; 8, lower discharge hopper; 9, discharge port; 10, side smoke outlet; 11, integrated side plate box; 12, heat exchange pipe; 13, discharge port; 14, intercepting fin; 15, heat exchange pipe; 16, negative pressure pipe; 17, rear smoke inlet; 18, airtight partition. DETAILED DESCRIPTION

[0013] Please refer to Figures 1-6 The present application provides a technical solution: a novel erosion corrosion resistant waste heat recovery heat exchanger, comprising an upper shell 1, a lower shell 2, an integrated side plate box 11 and a heat exchange pipe 12, the lower shell 2 is connected to the bottom end face of the upper shell 1 and communicates with the inside thereof, the upper shell 1 and the lower shell 2 are both welded with the integrated side plate box 11 at the opposite inner side walls, the heat exchange pipe 12 is integrally formed between the two groups of integrated side plate boxes 11 at the lower position and is parallel to each other, the smooth surface can disturb the flow of flue gas, reduce the direct impact of high-temperature high-speed flue gas, and the dense array distribution can realize preheating and heat exchange while dispersing the impact force of flue gas, thereby reducing the erosion and wear; further comprising a discharge port 13 and an intercepting fin 14, the discharge port 13 is integrally formed on the upper position of the two groups of integrated side plate boxes 11 and is parallel to each other, the intercepting fin 14 is connected between the two groups of integrated side plate boxes 11 and is parallel to the heat exchange pipe 12, the intercepting fin 14 is in inverted V-shaped structure and is located directly above the discharge port 13, the inverted V-shaped intercepting fin 14 can intercept the particles in the flue gas, so that the particles are gathered inside, and then cooperate with the discharge port 13 to absorb the dust particles by the negative pressure of the negative pressure pipe 16, thereby reducing the amount of particles entering the lower heat exchange pipe 12 area and reducing local erosion and wear.

[0014] The inner side of the intercepting fin 14 is inlaidly installed with a closed partition plate 18 for partition between the inner side wall of the upper shell 1, the closed partition plate 18 is located between the heat exchange pipe 12 and the intercepting fin 14, can form a partition, prevent the intercepted particles or flue gas from directly impacting the heat exchange pipe 12, further reduce the scouring; the lower shell 2 is integrally connected with the coaxially arranged smoke inlet pipe 4 and the rear smoke inlet 17 at the front and rear outer walls respectively, which provides a stable channel for the flue gas to enter and ensures the flue gas flow efficiency; the upper shell 1 is integrally connected with the heat exchange pipe 15 which is coaxially arranged and respectively communicated with the inside of the front and rear intercepting fins 14 of the upper shell 1 at the front and rear outer walls, the heat exchange pipe 15 is communicated with the heat exchange pipe 12 through the intercepting fin 14, the upper shell 1 is integrally connected with the negative pressure pipe 16 which is coaxially arranged and respectively communicated with the inside of the front and rear intercepting fins 14 of the upper shell 1 at the front and rear outer walls, the negative pressure pipe 16 is communicated with the discharge port 13 through the intercepting fin 14, which assists the absorption of the accumulated particles by means of negative pressure, enhances the recovery effect and avoids the secondary scouring of particles; the upper shell 1 is welded with the conical upper smoke stack 3 at the top, the upper smoke stack 3 is integrally provided with the smoke outlet 6 which is communicated with the inside of the upper smoke stack 3 at the top, the side wall of the upper smoke stack 3 is provided with the maintenance opening 7 which is communicated with the inside of the upper smoke stack 3, the flange and the cover plate are arranged on the smoke inlet pipe 4, the maintenance opening 7 and the negative pressure pipe 16 for closing, the upper smoke stack 3 and the smoke outlet 6 ensure the smooth discharge of flue gas, the maintenance opening 7 is convenient for equipment maintenance, and the overall flue gas treatment efficiency is ensured.

[0015] Secondly, the side wall of the upper smoke stack 3 is integrally connected with the side smoke outlet 10 which is communicated with the inside of the upper smoke stack 3, the side wall of the lower shell 2 is integrally connected with the side smoke inlet 5 which is communicated with the inside of the lower shell 2 and perpendicular to the axis of the smoke inlet pipe 4, which provides a multi-channel flue gas flow path and further ensures the flue gas flow efficiency; the lower shell 2 is welded with the inverted conical lower discharge hopper 8 at the bottom, the lower discharge hopper 8 is communicated with the inside of the lower shell 2, the bottom of the lower discharge hopper 8 is integrally connected with the discharge port 9 which is communicated with the inside of the lower discharge hopper 8, which can collect the accumulated particles and guide them out through the discharge port 9, avoiding the secondary scouring caused by the particles being carried by the flue gas again after accumulation; the diameter of the heat exchange pipe 12 is equal to the diameter of the discharge port 13, the inner edge length of the intercepting fin 14 is equal to the diameter of the discharge port 13; the distance between the two adjacent groups of heat exchange pipes 12 is equal to the diameter of the heat exchange pipe 12, and the distance between the two adjacent groups of discharge ports 13 is greater than the diameter of the discharge port 13, such size and distance design not only ensures the heat exchange efficiency, but also reduces the problem of local scouring aggravation caused by unreasonable structure.

[0016] Working principle: connect the smoke inlet pipe 4 and the rear smoke inlet 17 with the pipe for conveying the flue gas, connect the smoke outlet 6 and the side smoke outlet 10 with the pipe for discharging the flue gas, then connect the negative pressure pipe 16 on the front and rear side of the upper shell 1 with the air pumping equipment and the exhaust pipe respectively, finally connect the heat exchange pipe 15 on the front and rear side of the upper shell 1 with the water conveying pipe and the water discharging pipe respectively; start to convey the flue gas into the upper shell 1, when the flue gas passes through the heat exchange pipe 12, the heat exchange pipe 12 realizes preheating and heat exchange, at the same time its smooth surface and the dense distribution disperse the impact of the flue gas to reduce the abrasion; the interception fin 14 intercepts the particles in the flue gas, the particles are gathered in the interception fin 14, then are discharged by the negative pressure effect of the discharge port 13 and the negative pressure pipe 16, reduce the local scouring to the heat exchange pipe 12, guarantee the stable operation of the equipment.

[0017] The above has made the detailed description to the embodiments of the present application combined with the drawings, but the present application is not limited to the above embodiments, within the knowledge range of the ordinary skilled in the art, various changes can be made without departing from the purpose of the present application.

Claims

1. A new type of erosion and corrosion resistant waste heat recovery heat exchanger, characterized in that: include: An upper shell (1), a lower shell (2), an integrated side panel box (11) and a heat exchange tube (12), wherein the lower shell (2) is connected to the bottom end surface of the upper shell (1) and communicates with the interior thereof, integrated side panel boxes (11) are welded to the inner side walls opposite to each other on the inner sides of the upper shell (1) and the lower shell (2), and the heat exchange tubes (12) are distributed in a plurality of arrays and are integrally formed parallel to each other at a position near the bottom between the two groups of integrated side panel boxes (11); The discharge port (13) and the intercepting fin (14) are arranged in a plurality of arrays and are integrally formed parallel to each other at positions near the top of the two sets of integrated side panel boxes (11). The intercepting fin (14) is connected between the two sets of intercepting fins (14) and is parallel to the heat exchange tube (12). The intercepting fin (14) is in an inverted V-shaped structure and is located directly above the discharge port (13).

2. The novel erosion-corrosion resistant waste heat recovery heat exchanger according to claim 1 is characterized in that: A sealed partition (18) for partitioning is embedded and installed between the inner side of the intercepting fin (14) and the inner side wall of the upper shell (1), and the sealed partition (18) is located between the heat exchange tube (12) and the intercepting fin (14); and the front and rear outer walls of the lower shell (2) are respectively integrally connected with a coaxially arranged smoke inlet pipe (4) and a rear smoke inlet port (17).

3. The novel erosion-corrosion resistant waste heat recovery heat exchanger according to claim 2 is characterized in that: The front and rear outer walls of the upper shell (1) are integrally connected with heat exchange tubes (15) that are coaxially arranged and respectively communicated with the interiors of the front and rear intercepting fins (14) of the upper shell (1). The heat exchange tubes (15) are communicated with the heat exchange tubes (12) through the intercepting fins (14). The front and rear outer walls of the upper shell (1) are integrally connected with negative pressure tubes (16) that are coaxially arranged and respectively communicated with the interiors of the front and rear intercepting fins (14) of the upper shell (1). The negative pressure tubes (16) are communicated with the discharge port (13) through the intercepting fins (14).

4. The novel erosion-corrosion resistant waste heat recovery heat exchanger according to claim 3 is characterized by: A cone-shaped upper smoke exhaust pipe (3) is welded to the top of the upper shell (1), and a smoke exhaust port (6) communicating with the interior of the upper smoke exhaust pipe (3) is integrally formed on the top of the upper smoke exhaust pipe (3). An inspection port (7) communicating with the interior of the upper smoke exhaust pipe (3) is installed on the side wall of the upper smoke exhaust pipe (3), and a flange and a cover plate for sealing are provided on the smoke inlet pipe (4), the inspection port (7) and the negative pressure pipe (16).

5. The novel erosion-corrosion resistant waste heat recovery heat exchanger according to claim 4 is characterized in that: The side wall of the upper smoke exhaust duct (3) is integrally connected to a side smoke exhaust port (10) communicating with the interior thereof, and the side wall of the lower shell (2) is integrally connected to a side smoke inlet (5) communicating with the interior thereof and perpendicular to the axis of the smoke inlet pipe (4).

6. The novel erosion-corrosion resistant waste heat recovery heat exchanger according to claim 5 is characterized by: The bottom of the lower shell (2) is welded with an inverted conical lower discharge hopper (8), which is connected to the interior of the lower shell (2). The bottom of the lower discharge hopper (8) is integrally connected with a discharge port (9) that is connected to the interior of the lower shell (2).

7. The novel erosion-corrosion resistant waste heat recovery heat exchanger according to claim 6 is characterized by: The diameter of the heat exchange tube (12) is equal to the diameter of the discharge port (13), and the inner side length of the corner of the intercepting fin (14) is equal to the diameter of the discharge port (13).

8. The novel erosion-corrosion resistant waste heat recovery heat exchanger according to claim 7 is characterized in that: The distance between two adjacent groups of heat exchange tubes (12) is equal to the diameter of the heat exchange tubes (12), and the distance between two adjacent groups of discharge ports (13) is greater than the diameter of the discharge ports (13).

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