Converter flue gas waste heat recovery device

Abstract

The present invention provides a converter flue gas waste heat recovery device, comprising a tower body, a flue gas inlet, a flue gas outlet, and a heat exchange panel; the heat exchange panel is disposed in the upper region of the tower body, below the flue gas inlet. Compared to existing flue gas cooling technologies that rely solely on spray cooling, the present invention recovers waste heat from the high-temperature section of the converter flue gas, generating high-quality medium- and high-pressure saturated steam. This reduces the amount of water sprayed, the flue gas flow at the spray tower outlet, and the subsequent processing costs of the converter flue gas. The spray device in the middle and lower sections remains unchanged, without changing the existing spray operation.

Description

Technical Field

[0001] The invention belongs to the technical field of converter flue gas waste heat recovery devices, and in particular relates to a converter flue gas waste heat recovery device with dry dust removal. Background Art

[0002] The converter gas of ~1600℃ coming out of the steelmaking converter (some people call it converter flue gas, because it contains the combustible component CO, its content is as high as more than 70%, and the rest is CO2 and O2, so it is also called converter gas. It also contains a lot of dust, and the dust contains more usable components such as iron and magnesium, which need to be recovered) first enters the vaporization cooling flue waste heat boiler and cools down to ~1000℃. The dust in this temperature range is soft and has less abrasiveness to the metal wall. At present, the use of vaporization cooling flue waste heat boiler is relatively common, and almost every converter is equipped with it. The characteristics of converter gas: high temperature, high dust content, magnetism, abrasiveness, static electricity, intermittent, periodic, flammability, and extremely harsh conditions.

[0003] Converter gas at temperatures of ~1000°C is subject to significant wear and tear on metal surfaces due to the hardened dust. Currently, this gas is cooled to ~200°C with cold water in a spray cooling tower before being purified. Currently, no equipment worldwide has successfully recovered the heat from this ~1000°C converter flue gas, resulting in a waste of high-quality heat. Summary of the Invention

[0004] Technical problem: In order to solve the defects of the prior art, the present invention provides a converter flue gas waste heat recovery device with dry dust removal, which can effectively recover the converter flue gas waste heat.

[0005] Technical solution: The present invention provides a converter flue gas waste heat recovery device, in particular a converter flue gas waste heat recovery device for dry dust removal, comprising a tower body, a flue gas inlet, a flue gas outlet and a heat exchange panel; the heat exchange panel is arranged in the upper area inside the tower body, below the flue gas inlet.

[0006] As a preferred or improved solution:

[0007] The heat exchange panels are evenly distributed along the circumferential direction in the tower body and placed radially, and can absorb and recover the waste heat of the converter flue gas.

[0008] The heat exchange panel is a composite energy panel, and several of them are combined into a composite energy panel assembly device; the composite energy panel includes an outer shell and an internal heat-conducting medium layer and a heat exchange tube. The heat exchange tube is buried in the heat-conducting medium layer, and its two ends are opened to the outside of the outer shell and connected to the heat exchange medium pipeline outside the tower body.

[0009] The flue gas inlet can be arranged at the top of the tower body, or on the wall of the tower body near the top, or at the upper part of the tower body; the flue gas outlet can be arranged at the bottom of the tower body, or on the wall of the tower body near the bottom, or at the lower part of the tower body, all of which can achieve the purpose of the present invention.

[0010] The composite energy panels are evenly distributed along the circumference of the tower body and arranged in a vertical wall. The composite energy panels are thin, large, and moderately wide. The vertical wall arrangement is suitable for external smoke to flush longitudinally along the vertical panel surface.

[0011] The composite energy board also includes an anti-wear cover, which is located at the top of the composite energy board and is equipped with a vertical plate and inclined plates on both sides of the vertical plate. The anti-wear cover protects the composite energy board from wear, and the vertical plate on the top and the inclined plates on both sides respectively guide dust.

[0012] Further preferably, the angle between the vertical plate and the inclined plate is θ, which needs to conform to the repose angle of the dust to ensure that the dust can fall smoothly.

[0013] The outer surface of the shell is further provided with straight fins, preferably arranged from top to bottom, which serve to expand the heat exchange surface.

[0014] The housing must be resistant to high temperatures, wear and demagnetization.

[0015] The heat exchange tubes are distributed in a serpentine structure and are arranged in parallel in several groups.

[0016] The converter flue gas waste heat recovery device also includes a spray device arranged below the composite energy plate assembly device, the spray device includes a conveying pipeline and a nozzle arranged inside the tower body, and a cold medium inlet arranged on the side wall of the tower body. The nozzle is installed on the conveying pipeline, and the conveying pipeline is connected to the cold medium inlet.

[0017] The heat exchange tubes in the composite energy plate have their lower openings connected to the water inlet main pipe, and their upper openings are connected to the steam-water main pipe. The water inlet main pipe and the steam-water main pipe are both connected to the steam drum outside the tower body. A forced circulation pump is also provided on the pipeline connecting the steam drum and the water inlet main pipe, together forming a circulation path for the cooling medium.

[0018] Since the dust content in the flue gas is relatively high, generally reaching 150 g / m 3More than that, and the particles are relatively large, some even have a particle size of more than 2mm. The dust contains a variety of metal elements, so the dust will cause serious wear on the wall surface. The collision of metal particles during the flow process will generate static electricity, which has adsorptive and magnetic properties. The composite energy plate used in the present invention is arranged as a vertical wall surface. The windward width of the composite energy plate is very small, so it will not occupy a large area of ​​flue gas circulation. In other words, after the composite energy plate is set, the flow rate of the flue gas remains almost unchanged, and the wear on the composite energy plate will not occur due to a much larger flue gas flow rate. The composite energy plate is made of high-temperature resistant and non-magnetic material (such as high-temperature resistant stainless steel material), which will not allow magnetic dust to be adsorbed on the composite energy plate, so as to keep the plate surface clean and ensure continuous and efficient heat transfer.

[0019] Due to the intermittent and periodic operation of the converter, the present invention adopts a forced circulation waste heat boiler to recover the heat of the flue gas. It is designed according to the operating conditions of the maximum flue gas flow rate and the highest flue gas inlet temperature. Under the minimum operating conditions, the flue gas flow rate may be 0, but the circulation of the heat exchange medium is still in progress. The heat exchange medium circulates at a constant flow rate and will not change due to changes in the flue gas flow rate and temperature. This can reduce the thermal shock of the heat exchange medium and increase the stability of the cycle.

[0020] Beneficial effects: Compared with the existing technology that relies entirely on spray cooling to cool the flue gas, the present invention recovers the waste heat from the high-temperature section of the converter flue gas, can produce high-grade medium and high-pressure saturated steam, reduces the amount of water sprayed, reduces the flue gas flow at the spray tower outlet, reduces the subsequent treatment cost of the converter flue gas, removes the spray device at the top of the spray tower, retains the spray device in the middle and lower parts, and does not change the original spray operation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the converter flue gas waste heat recovery device of the present invention.

[0022] Figure 2 It is a cross-sectional view of the composite energy plate in the converter flue gas waste heat recovery device of the present invention.

[0023] Figure 3 This is a schematic diagram (top view) of the distribution of the composite energy plates in the converter flue gas waste heat recovery device of the present invention.

[0024] Figure 4 It is a structural schematic diagram of the composite energy plate anti-wear cover in the converter flue gas waste heat recovery device of the present invention.

[0025] Figure 5 This is a schematic diagram of the surface structure of the composite energy plate in the converter flue gas waste heat recovery device of the present invention.

[0026] Figure 6 The figure is a schematic diagram of the structure and distribution of heat exchange tubes in the converter flue gas waste heat recovery device of the present invention.

[0027] Figure 7 This is a diagram showing the connection relationship between the heat exchange tubes and the steam drum in the converter flue gas waste heat recovery device of the present invention. DETAILED DESCRIPTION

[0028] The following is a further description of a converter flue gas waste heat recovery device with dry dust removal according to the present invention in conjunction with the accompanying drawings.

[0029] Example 1

[0030] Dry dust removal converter flue gas waste heat recovery device, such as Figure 1-6 As shown, it includes a tower body 1, a flue gas inlet 2 at the top of the tower body 1, a flue gas outlet 3 at the bottom of the tower body 1, a composite energy plate assembly device 4, a spray device 5 below the composite energy plate assembly device 4 and a steam drum 6 outside the tower body 1.

[0031] The composite energy plate assembly device 4 is arranged in the upper area inside the tower body 1, below the flue gas inlet 2, to absorb the heat released by the high-temperature flue gas. The composite energy plate assembly device 4 is mainly composed of several composite energy plates 40, such as Figure 3 As shown, the composite energy panels 40 are evenly distributed along the circumference of the tower body 1 and arranged radially (with the panels arranged vertically). The composite energy panels 40 are thin, tall, and moderately wide. Their vertical wall arrangement allows for the longitudinal flushing of external flue gas along the vertical panel surfaces. The composite energy panels 40 comprise a shell 401, an internal heat transfer medium layer 402 and heat exchange tubes 403, a wear-resistant cover 404 at the top of the shell 401, and straight fins 405 on the outer surface of the shell 401.

[0032] like Figure 2 As shown, the heat exchange tube 403 is buried in the heat conducting medium layer 402, and its two ends are opened to the outside of the shell 401 and connected to the heat exchange medium pipeline outside the tower body 1. Figure 4 As shown, the top of the anti-wear cover 404 is provided with a vertical plate 4041 and inclined plates 4042 on both sides of the vertical plate 4041. The anti-wear cover 404 protects the composite energy plate 40 from wear, and the vertical plate 4041 on the top and the inclined plates 4042 on both sides respectively guide the dust. The angle of the vertical plate 4041 and the inclined plate 4042 is θ, which needs to conform to the repose angle of the dust to ensure that the dust can fall smoothly. Figure 5 As shown, the straight fins 405 are arranged from top to bottom to expand the heat exchange surface. The shell 401 must be resistant to high temperature, wear and demagnetization. Figure 6 As shown, the heat exchange tubes 403 are distributed in a serpentine structure and are arranged in parallel in several groups.

[0033] The spray device 5 includes a delivery pipeline 51 and a nozzle 52 provided inside the tower body 1 , and a cold medium inlet 53 provided on the side wall of the tower body 1 . The nozzle 52 is installed on the delivery pipeline 51 , and the delivery pipeline 51 is connected to the cold medium inlet 53 .

[0034] like Figure 7 As shown, the heat exchange tubes 403 in the composite energy plate 40 have their lower openings connected to the water inlet main pipe 406, and their upper openings are connected to the steam-water main pipe 407. The water inlet main pipe 406 and the steam-water main pipe 407 are both connected to the steam drum 6 outside the tower body 1. A forced circulation pump 61 is also provided on the pipeline connecting the steam drum 6 and the water inlet main pipe 406, which together form a circulation path for the cooling medium.

[0035] It should be noted that the flue gas inlet 2 can be arranged at the top of the tower body 1, or on the wall of the tower body 1 near the top, or on the upper part of the tower body 1; the flue gas outlet 3 can be arranged at the bottom of the tower body 1, or on the wall of the tower body 1 near the bottom, or on the lower part of the tower body 1, all of which can achieve the purpose of the present invention.

[0036] In addition, the composite energy panel assembly device 4 can be replaced by any heating panel, and the purpose of the present invention can be achieved. The heating panel is a plate-like structure used for heating.

[0037] The working principle of the above converter flue gas waste heat recovery device is as follows:

[0038] After absorbing the heat released by the high-temperature converter gas, the shell 401 (and the straight fins 405 ) of the composite energy panel 40 transfers the heat to the high thermal conductivity medium layer 402 , which then transfers the heat to the heat exchange tube 403 and finally to the water in the heat exchange tube 403 .

[0039] The saturated water coming out of the drum 6 is driven by the forced circulation pump 61 and sent into the heat exchange tube 403. After absorbing the heat released by the coal gas, it becomes a steam-water mixture and is sent to the drum 6. After the steam and water are separated, the saturated steam is sent out and the saturated water participates in the circulation again. The more specific circulation method is as follows:

[0040] The saturated water coming down from the drum 6 is driven by the forced circulation pump 61 into the water inlet main 406. The water inlet main 406 distributes the saturated water to the water inlets at the lower ends of the heat exchange tubes 403 of each composite energy panel 40. After absorbing the heat released by the coal gas, the saturated water turns into a steam-water mixture. The mixture is then discharged through the upper ends of the heat exchange tubes 403 and collected into the steam-water main 407, and finally enters the drum 6. After the steam and water are separated, the saturated steam is sent out and the saturated water participates in the circulation again.

Claims

1. A converter flue gas waste heat recovery device, characterized in that: The invention comprises a tower body (1), a flue gas inlet (2), a flue gas outlet (3) and a heat exchange panel; the heat exchange panel is arranged in the upper area inside the tower body (1) and below the flue gas inlet (2); the heat exchange panel is evenly distributed along the circumferential direction inside the tower body (1) and is placed radially; the heat exchange panel is a composite energy plate (40), and a plurality of composite energy plate combination devices (4) are combined to form a composite energy plate combination device (4); the composite energy plate (40) comprises an outer shell (401) and an inner heat-conducting medium layer (402) and a heat exchange tube (403); the heat exchange tube (403) is buried in the heat-conducting medium layer (402), and its two ends are open and extend to the outside of the outer shell (401) and are connected to the heat exchange medium pipeline outside the tower body (1); the outer surface of the outer shell (401) is also provided with straight fins (405); the heat exchange tubes (403) are distributed in a serpentine structure and are arranged in parallel in a plurality of groups; The converter flue gas waste heat recovery device further comprises a spray device (5) arranged below the composite energy plate assembly device (4), the spray device (5) comprising a delivery pipeline (51) and a nozzle (52) arranged inside the tower body (1), and a cold medium inlet (53) arranged on the side wall of the tower body (1), the nozzle (52) being installed on the delivery pipeline (51), and the delivery pipeline (51) being connected to the cold medium inlet (53).

2. The converter flue gas waste heat recovery device according to claim 1, characterized in that: The composite energy plate (40) further comprises an anti-wear cover (404), which is located at the top of the composite energy plate (40), and has a vertical plate (4041) and inclined plates (4042) on both sides of the vertical plate (4041) provided on the top.

3. The converter flue gas waste heat recovery device according to claim 2, characterized in that: The angle between the vertical plate (4041) and the inclined plate (4042) is θ, which needs to conform to the repose angle of dust.

4. The converter flue gas waste heat recovery device according to claim 1, characterized in that: The housing (401) must be resistant to high temperatures, wear and tear, and demagnetization.

5. The converter flue gas waste heat recovery device according to claim 1, characterized in that: The heat exchange tubes (403) in the composite energy plate (40) have lower openings connected to the water inlet main pipe (406) and upper openings connected to the steam-water main pipe (407). The water inlet main pipe (406) and the steam-water main pipe (407) are both connected to the steam drum (6) outside the tower body (1). A forced circulation pump (61) is also provided on the pipeline connecting the steam drum (6) and the water inlet main pipe (406), together forming a circulation path for the cooling medium.

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