A compact falling film boiler for a carbon dioxide chemical absorption system and method of use thereof

Abstract

The application discloses a compact falling-film boiler of a carbon dioxide chemical absorption system and a use method thereof, and relates to the field of chemical absorption systems, and particularly relates to a compact falling-film boiler of a carbon dioxide chemical absorption system and a use method thereof. The compact falling-film boiler comprises a heat exchange core body and a liquid distributor arranged on the upper surface of the heat exchange core body. The liquid distributor comprises a first surrounding plate, a second surrounding plate and a plurality of liquid flow guide plates. The first surrounding plate and the second surrounding plate form independent spaces for placing the liquid flow guide plates. Square grooves for flowing of lean absorbent liquid are arranged between two adjacent liquid flow guide plates. The surface of each liquid flow guide plate is linearly provided with through holes. The liquid distributor is used for uniformly entering the lean absorbent liquid into the heat exchange core body downwards. The lean absorbent liquid is evaporated along the heat exchange core body downwards, and water vapor and the lean absorbent liquid are separated in countercurrent or concurrent flow. The application has simple overall structure, is convenient to use, can realize uniform distribution of the lean liquid, and enhances the overall heat exchange performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of carbon dioxide chemical absorption system, in particular to a compact falling film boiler for carbon dioxide chemical absorption system and a method of using the same. BACKGROUND

[0002] The typical process flow of chemical absorption method is that the flue gas of power plant is cooled, dedusted and deeply desulfurized and denitrated in a pretreatment tower, and then enters an absorption tower to be in countercurrent contact with lean liquid, the absorption liquid that absorbs carbon dioxide in the flue gas is called rich liquid, the cold rich liquid is sent to a desorption tower, a reboiler installed at the bottom of the desorption tower generates secondary steam to drive the regeneration of hot rich liquid, and the regenerated gas is cooled in a regenerated gas cooler to produce high-purity carbon dioxide gas.

[0003] The reboiler used at present is usually a tubular heat exchanger, in which steam passes through the shell side and lean liquid passes through the tube side. For example, the Chinese patent document with publication number CN101053696A discloses a central tube falling film dry kettle reboiler, and the Chinese patent document with publication number CN103143248A discloses an absorption and desorption system for low-content carbon dioxide in industrial waste gas. The heat exchange effect of the tubular heat exchanger is not as good as that of the plate heat exchanger, but the tubular heat exchanger is easier to clean, the plate heat exchanger is small in size and low in equipment investment, but difficult to maintain.

[0004] Therefore, a heat exchanger is needed that combines the features of plate heat exchangers and tubular heat exchangers, has excellent heat exchange, is small in size, easy to clean and easy to maintain. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, the present application provides a compact falling film boiler for carbon dioxide chemical absorption system and a method of using the same, which is simple in overall structure, convenient to use, can realize uniform distribution of lean liquid and enhance the overall heat exchange performance.

[0006] A compact falling film boiler for carbon dioxide chemical absorption system, comprising a heat exchange core and a liquid distributor arranged on the upper surface of the heat exchange core.

[0007] The liquid distributor comprises a first enclosing plate, a second enclosing plate and a plurality of liquid guide plates, the first enclosing plate and the second enclosing plate form an independent space for placing the liquid guide plates, a square groove for the flow of lean absorption liquid is arranged between adjacent two liquid guide plates, and a through hole is linearly arranged on the surface of each liquid guide plate.

[0008] The liquid distributor is used for uniformly downwardly entering the absorbent lean liquid into the heat exchange core, and the absorbent lean liquid is evaporated along the heat exchange core to realize the countercurrent or cocurrent separation of water vapor and the absorbent lean liquid.

[0009] Further, the first surrounding plate and the second surrounding plate are connected through a limiting mechanism.

[0010] Further, the limiting mechanism comprises a groove opened at two ends of the first surrounding plate towards the second surrounding plate, springs are arranged on the upper and lower sides of the groove, moving plates are arranged at one end of the two springs close to each other, and a limiting plate is connected to one end of the moving plate away from the spring; and a limiting groove matched with the limiting plate is opened on one side of the second surrounding plate close to the limiting plate.

[0011] Further, grooves are opened on the left and right sides in the groove, and sliding blocks matched with the grooves are arranged at two ends of the moving plate, and a lubricating unit is arranged at one end of the sliding block extending into the groove.

[0012] Further, the lubricating unit comprises a strip-shaped groove opened at one end of the sliding block close to the groove, and a connecting rod and a roller are arranged in the strip-shaped groove, the roller is arranged on the connecting rod, and the roller abuts against the groove.

[0013] Further, the heat exchange core comprises a plurality of heat exchange plates, and a gap for the flow of the absorbent lean liquid is reserved between every two heat exchange plates.

[0014] Further, a vertical concave-convex structure is arranged on the surface of each heat exchange plate in an array, the shape is 4mm long, 3mm wide and 3mm deep, and the absorbent lean liquid is uniformly distributed on the inner wall of the heat exchange plate by means of the vertical concave-convex structure.

[0015] A method for using a compact falling film boiler of a carbon dioxide chemical absorption system, comprising:

[0016] S1, first press the limiting plate, the roller slides in the groove, drives the movement of the sliding block, so that the two moving plates are close to each other, drive the two limiting plates to limit close, and at the same time stretch the spring;

[0017] S2, insert the limiting plates close to each other into the corresponding limiting grooves on the second surrounding plate, when the limiting plates lose the pressing, the spring is deformed, the elastic potential energy is converted into kinetic energy to act on the limiting plate, at this time, the sliding block slides in the groove under the driving of the roller, the two moving plates are away from each other, and the two limiting plates move towards opposite directions until they are inserted into the limiting grooves;

[0018] S3, pour the absorbent hot lean liquid into the distribution pipe, flow into the liquid distributor from the distribution pipe, the absorbent lean liquid is guided by the liquid guide plate, flows through the through hole in the square groove, and is uniformly distributed on the inner wall of the heat exchange plate by the vertical concave-convex structure;

[0019] S4, the absorbent lean liquid evaporates along the heat exchange plate, and the water vapor is separated from the absorbent lean liquid in countercurrent or cocurrent;

[0020] S5, after the device is operated for a long period of time, the heat exchange efficiency is reduced due to the attachment and precipitation of liquid impurities, and the plate hole is blocked, so that the whole device is quickly disassembled for cleaning.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] In the present application, when the absorbent hot lean liquid enters the liquid distributor from the distribution pipe, the absorbent lean liquid is uniformly distributed on the inner wall of the heat exchange plate by the liquid guide plate, and the vertical concave-convex structure uniformly distributes the absorbent lean liquid to form a uniform liquid film, the absorbent lean liquid evaporates along the heat exchange plate, and the water vapor is separated from the absorbent lean liquid in countercurrent or cocurrent, so that the uniform distribution of the lean liquid is realized, and the overall heat exchange performance is enhanced. And by limiting the approach of the two limiting plates, and simultaneously stretching the spring, the limiting plates close to each other are inserted into the corresponding limiting grooves on the second enclosing plate, when the limiting plates lose the pressing, the spring deforms, and the elastic potential energy is converted into kinetic energy to react on the limiting plates. At this time, the sliding block slides in the sliding groove under the drive of the roller, drives the two moving plates to move away from each other, and moves the two limiting plates in opposite directions until they are inserted into the limiting grooves, the first enclosing plate and the second enclosing plate are spliced, and a combined liquid distributor is formed. The overall structure is simple, convenient to use, the size of the boiler is reduced, and the equipment investment is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a three-dimensional structure schematic diagram of the present application;

[0024] Figure 2 It is a structure schematic diagram of the heat exchange plate in the present application;

[0025] Figure 3 It is a structure schematic diagram of the liquid distributor in the present application;

[0026] Figure 4 It is a structure schematic diagram of the heat exchange core in the present application;

[0027] Figure 5 It is a front view of the heat exchange plate in the present application;

[0028] Figure 6 It is a structure schematic diagram of the first enclosing plate in the present application;

[0029] Figure 7 It is aFigure 6 Enlarged schematic diagram of the structure at point A in the middle;

[0030] Figure 8 This is a schematic diagram of the lubrication unit in this invention;

[0031] Figure 9 A heat exchange comparison diagram of a tubular falling film boiler and the compact falling film boiler of this invention;

[0032] Figure 10 A heat exchange comparison diagram of a boiling vessel without a vertical concave-convex structure and a falling film boiling vessel with a vertical concave-convex structure according to the present invention.

[0033] In the diagram: 1. First enclosure plate; 2. Second enclosure plate; 3. Liquid guide plate; 4. Through hole; 5. Heat exchange plate; 6. Groove; 7. Spring; 8. Moving plate; 9. Limiting plate; 10. Slide groove; 11. Sliding block; 12. Connecting rod; 13. Roller; 14. Limiting groove. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments described below are intended to facilitate the understanding of the present invention and do not constitute any limitation thereof.

[0035] like Figures 1-8 As shown, this embodiment proposes a compact falling film boiler for a carbon dioxide chemical absorption system, including a liquid distributor and a heat exchange core. The liquid distributor is disposed on the upper surface of the heat exchange core. The absorbent lean liquid is evenly distributed in the heat exchange core through the liquid distributor. The absorbent lean liquid evaporates downward along the heat exchange core, realizing the countercurrent or cocurrent separation of water vapor and absorbent lean liquid. Two limiting plates 9 are brought close together, and the spring 7 is stretched at the same time. The mutually close limiting plates 9 are inserted into the corresponding limiting grooves 14 on the second enclosure 2. When the limiting plates 9 are released from pressure, the spring 7 deforms and converts the elastic potential energy into kinetic energy to react with the limiting plates 9. At this time, the slider 11 slides in the slide groove 10 under the drive of the roller 13, which drives the two moving plates 8 away from each other and moves the two limiting plates 9 in opposite directions until they are inserted into the limiting grooves 14, completing the splicing of the first enclosure 1 and the second enclosure 2 to form a combined liquid distributor. The overall structure is simple and easy to use. When the absorbent liquid enters the liquid distributor through the distribution pipe, the absorbent liquid is distributed on the inner wall of the heat exchange plate 5 through the liquid guide plate 3. The absorbent liquid can evaporate downward along the heat exchange plate 5. The water vapor and the absorbent liquid are separated by countercurrent or parallel flow. This facilitates the uniform distribution of the liquid on the heat exchange plate, thereby enhancing the heat exchange performance.

[0036] like Figures 4-5As shown, the heat exchange core includes a plurality of heat exchange plates 5, and a gap for the flow of lean absorbent liquid is reserved between every two heat exchange plates 5. Each heat exchange plate 5 is provided with a vertical concave-convex structure, which has a shape of 4 mm in length, 3 mm in width and 3 mm in depth. The lean absorbent liquid is uniformly distributed on the inner wall of the heat exchange plate 5 by means of the vertical concave-convex structure.

[0037] In order to facilitate the quick assembly of the first surrounding plate 1 and the second surrounding plate 2, the liquid distributor includes the first surrounding plate 1 and the second surrounding plate 2 and a plurality of liquid flow guide plates 3, the first surrounding plate 1 and the second surrounding plate 2 form independent spaces for placing the liquid flow guide plates 3, a square groove for the flow of lean absorbent liquid is provided between every two liquid flow guide plates 3, and a through hole 4 is linearly distributed on the surface of each liquid flow guide plate 3. The lean absorbent liquid flows in the square groove and flows to the surface of the heat exchange plate 5 through the through hole 4. The independent spaces facilitate the arrangement of the liquid flow guide plates 3. A plurality of groups of plate-type heat exchange plates 5 are arranged to improve the heat exchange performance, and the heat exchange plates 5 correspond to the liquid flow guide plates 3 in the independent spaces. The first surrounding plate 1 and the second surrounding plate 2 are connected through a limiting mechanism, which ensures the uniform distribution of the lean absorbent liquid in the heat exchange core, thereby maximizing the heat exchange efficiency. The limiting mechanism includes a groove 6 opened on the outer side of the two ends of the first surrounding plate 1 facing the second surrounding plate 2, springs 7 are arranged on the upper and lower sides of the groove 6, the elastic potential energy is converted into kinetic energy through the stretching of the springs 7, and the moving plate 8 is moved in reaction, so as to facilitate the mutual approach and mutual separation of the limiting plates 9, thereby realizing the splicing of the first surrounding plate 1 and the second surrounding plate 2.

[0038] Among them, the spring 7 is provided as two, the two springs 7 are provided with moving plates 8 at the close end, the moving plate 8 is connected with a limiting plate 9 at the end away from the spring 7, and the two limiting plates 9 are oppositely arranged to facilitate insertion into the limiting groove 14. The left and right sides of the groove 6 are both provided with a sliding groove 10, and the two ends of the moving plate 8 are both provided with a sliding block 11, and the sliding block 11 is provided with a lubricating unit at one end extending into the sliding groove 10.

[0039] As shown in the figure, Figures 7-8 The lubricating unit includes a strip-shaped groove opened on the end of the sliding block 11 close to the sliding groove 10, two connecting rods 12 and a roller 13 are arranged in the strip-shaped groove, the roller 13 is arranged between the two connecting rods 12, and the roller 13 abuts against the sliding groove 10. By rotating the roller 13 and abutting against the sliding groove 10, the roller 13 can slide in the sliding groove 10, drive the sliding block 11 to move, and make the moving plate 8 drive the limiting plate 9 to move. The second surrounding plate 2 is provided with a limiting groove 14 matched with the limiting plate 9 on the side close to the limiting plate 9, and the limiting plate 9 is inserted into the limiting groove 14 to complete the splicing of the first surrounding plate 1 and the second surrounding plate 2.

[0040] A method for using a compact falling film boiler of a carbon dioxide chemical absorption system, the specific steps are as follows:

[0041] S1. First, press the limiting plate 9, the roller 13 slides in the slide groove 10, driving the slider 11 to move, so that the two moving plates 8 move closer to each other, driving the two limiting plates 9 to move closer to each other, and at the same time stretching the spring 7.

[0042] S2. Insert the mutually close limiting plates 9 into the corresponding limiting grooves 14 on the second enclosure plate 2. When the limiting plates 9 lose pressure, the spring 7 deforms and converts the elastic potential energy into kinetic energy to react with the limiting plates 9. At this time, the slider 11 slides in the slide groove 10 under the drive of the roller 13, causing the two moving plates 8 to move away from each other and causing the two limiting plates 9 to move in opposite directions until they are inserted into the limiting grooves 14.

[0043] S3. Pour the absorbent lean liquid into the distribution pipe, and it flows into the liquid distributor through the distribution pipe. The absorbent lean liquid flows through the through hole 4 in the square groove through the guide plate 3, and is evenly distributed on the inner wall of the heat exchange plate 5.

[0044] S4. The lean absorbent solution evaporates downwards along the heat exchange plate 5, and the water vapor separates from the lean absorbent solution in countercurrent or parallel flow.

[0045] S5. After long-term operation, problems such as reduced heat exchange efficiency and blocked plate holes caused by the adhesion and precipitation of liquid impurities can be cleaned by quickly disassembling the equipment.

[0046] like Figure 9 As shown, in the heat exchange comparison between the tubular falling film boiler and the compact falling film boiler, when steam at 144℃ and 0.3MPa is introduced to heat water at 25℃ to 110℃, the heating time of the compact falling film boiler is 10min, which is less than the 11min of the tubular falling film boiler, and the equipment volume is reduced by 7%.

[0047] like Figure 10 As shown in the figure, in the heat exchange comparison between a boiling vessel without a vertical concave-convex structure and a falling film boiling vessel with a vertical concave-convex structure, steam at 144℃ and 0.3MPa was introduced to heat water at 25℃ to 110℃. The heating time of the falling film boiling vessel with the vertical concave-convex structure was 10 minutes, which was less than the 12 minutes of the tubular falling film boiling vessel. As can be seen from the figure, the vertical concave-convex structure can enhance the heat exchange efficiency.

[0048] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A compact falling-film boiler for a carbon dioxide chemical absorption system, characterized by, The heat exchange core and a liquid distributor arranged on the upper surface of the heat exchange core are included. The liquid distributor includes a first surrounding plate (1), a second surrounding plate (2) and a plurality of liquid flow guides (3), the first surrounding plate (1) and the second surrounding plate (2) form independent spaces for placing the liquid flow guides (3), a square groove for flowing of lean absorbent liquid is preset between two adjacent liquid flow guides (3), and a through hole (4) is linearly distributed on the surface of each liquid flow guide (3). The liquid distributor is used for making the lean absorbent liquid uniformly enter the heat exchange core, and the lean absorbent liquid evaporates along the heat exchange core to realize countercurrent or cocurrent separation of water vapor and the lean absorbent liquid. The first surrounding plate (1) and the second surrounding plate (2) are connected through a limiting mechanism, the limiting mechanism includes a groove (6) opened on the outer side of both ends of the first surrounding plate (1) facing the second surrounding plate (2), springs (7) are arranged on the upper and lower sides of the groove (6), a moving plate (8) is arranged on the end of each spring (7) close to the other, and a limiting plate (9) is connected to the end of the moving plate (8) away from the spring (7); a limiting groove (14) matched with the limiting plate (9) is opened on the side of the second surrounding plate (2) close to the limiting plate (9). Sliding grooves (10) are opened on the left and right sides in the groove (6), sliding blocks (11) matched with the sliding grooves (10) are arranged on both ends of the moving plate (8), a lubricating unit is arranged on the end of the sliding block (11) extending into the sliding groove (10); the lubricating unit includes a strip-shaped groove opened on the end of the sliding block (11) close to the sliding groove (10), a connecting rod (12) and a roller (13) are arranged in the strip-shaped groove, the roller (13) is arranged on the connecting rod (12), and the roller (13) abuts against the sliding groove (10). The heat exchange core includes a plurality of heat exchange plates (5), and a gap for flowing of lean absorbent liquid is reserved between each two heat exchange plates (5); a vertical concave-convex structure arranged in an array is arranged on the surface of each heat exchange plate (5), and the lean absorbent liquid is uniformly distributed on the inner wall of the heat exchange plate (5) by means of the vertical concave-convex structure.

2. The method of using a compact falling film boiler for a carbon dioxide chemical absorption system of claim 1, wherein, It includes: S1, first press the limiting plate (9), the roller (13) slides in the sliding groove (10), drives the movement of the sliding block (11), makes the two moving plates (8) close to each other, drives the two limiting plates (9) to limit close, and at the same time stretches the spring (7); S2, insert the limiting plates (9) close to each other into the corresponding limiting grooves (14) on the second surrounding plate (2), when the limiting plates (9) lose the pressing, the spring (7) is deformed, converts the elastic potential energy into kinetic energy and reacts on the limiting plate (9), at this time, the sliding block (11) slides in the sliding groove (10) under the driving of the roller (13), drives the two moving plates (8) to move away from each other, and makes the two limiting plates (9) move in opposite directions until they are inserted into the limiting grooves (14). S3, the absorbent hot lean liquid is poured into the distribution pipe, and flows into the liquid distributor from the distribution pipe. The absorbent lean liquid is guided by the liquid guide plate (3), flows through the through hole (4) in the square groove, and is uniformly distributed on the inner wall of the heat exchange plate (5) by relying on the vertical concave-convex structure; S4, the absorbent lean liquid evaporates downward along the heat exchange plate (5), and the water vapor is separated from the absorbent lean liquid in counterflow or parallel flow; S5, after long-period operation of the equipment, the heat exchange efficiency is reduced due to attachment and precipitation of liquid impurities, and the plate hole is blocked. The whole equipment is quickly disassembled for cleaning.

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