Compact falling film boiler of carbon dioxide chemical absorption system and use method of compact falling film boiler

Abstract

The invention discloses a compact falling film boiler of a carbon dioxide chemical absorption system and a use method of the compact falling film boiler. 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 guide plates, the first surrounding plate and the second surrounding plate form an independent space for placing the liquid guide plates, a square groove for circulating an absorbent barren solution is pre-formed between every two adjacent liquid guide plates, and through holes are linearly distributed in the surface of each liquid guide plate; the liquid distributor is used for enabling an absorbent barren solution to uniformly and downwards enter the heat exchange core body, and the absorbent barren solution is downwards evaporated along the heat exchange core body, so that reverse flow or parallel flow separation of water vapor and the absorbent barren solution is realized. The device is simple in overall structure and convenient to use, barren liquor can be evenly distributed, and the overall heat exchange performance is enhanced.

Description

Technical Field

[0001] The invention belongs to the field of carbon dioxide chemical absorption system, and in particular relates to a compact falling film boiler of the carbon dioxide chemical absorption system and a use method thereof. Background Art

[0002] Typical process flow of chemical absorption method: After the flue gas of the power plant is cooled, dust-removed, deeply desulfurized and denitrated in the pre-treatment tower, it enters the absorption tower and contacts with the lean liquid of the absorbent agent in countercurrent flow for heat and mass transfer. The absorbent that absorbs the carbon dioxide of the flue gas is called rich liquid. The cold rich liquid is sent to the desorption tower. The reboiler installed at the bottom of the desorption tower produces secondary steam to drive the regeneration of the hot rich liquid. After the regenerated gas is cooled by the regeneration gas cooler, high-purity carbon dioxide gas is produced. The regeneration of the absorption rich liquid is a heat-driven process. Usually, a reboiler is installed at the bottom of the regeneration tower. The lean liquid enters the reboiler and vaporizes to produce secondary water vapor, which countercurrently transfers heat and mass with the hot rich liquid.

[0003] The reboiler currently used is usually a tubular heat exchanger, with steam passing through the shell side and lean liquid passing 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 a low-content carbon dioxide absorption and analysis system in industrial waste gas. The heat exchange effect of the tubular heat exchanger is not as ideal as that of the plate heat exchanger, but the cleaning difficulty of the tubular heat exchanger is small, the plate heat exchanger is small in size, and the equipment investment is small, but it is difficult to maintain.

[0004] Therefore, a heat exchanger is needed that combines the characteristics of plate heat exchanger and tube heat exchanger, with the characteristics of excellent heat exchange, small size, easy cleaning and easy maintenance. Summary of the invention

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

[0006] A compact falling film boiler for a carbon dioxide chemical absorption system comprises 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, wherein the first enclosing plate and the second enclosing plate form an independent space for placing the liquid guide plates, a square groove for the circulation of absorbent lean liquid is preset between two adjacent liquid guide plates, and through holes are linearly distributed on the surface of each liquid guide plate;

[0008] The liquid distributor is used to make the absorbent lean liquid uniformly flow downward into the heat exchange core, and the absorbent lean liquid evaporates downward along the heat exchange core to achieve countercurrent or cocurrent separation of water vapor and absorbent lean liquid.

[0009] Furthermore, the first enclosure plate and the second enclosure plate are connected via a limiting mechanism.

[0010] Furthermore, the limiting mechanism includes a groove opened on the outer side of the first enclosure plate toward the two ends of the second enclosure plate, and springs are arranged on the upper and lower sides of the groove. A movable plate is arranged on the end close to the two springs, and the end of the movable plate away from the spring is connected to the limiting plate; the second enclosure plate is provided with a limiting groove adapted to the limiting plate on the side close to the limiting plate.

[0011] Furthermore, slide grooves are provided on the left and right sides of the groove, and sliding blocks matching the slide grooves are provided at both ends of the movable plate, and a lubrication unit is provided at one end of the sliding block extending into the slide groove.

[0012] Furthermore, the lubrication unit includes a strip groove opened at one end of the sliding block close to the sliding groove, a connecting rod and a roller are arranged in the strip groove, the roller is arranged on the connecting rod, and the roller abuts against the sliding groove.

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

[0014] Furthermore, the surface of each heat exchange plate is provided with an array of vertical concave-convex structures, which are 4 mm long, 3 mm wide and 3 mm deep. Relying on the vertical concave-convex structures, the absorption liquid and the lean liquid are evenly distributed on the inner wall of the heat exchange plate.

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

[0016] S1. First, press the limit plate, and the roller slides in the slide groove, driving the slider to move, so that the two moving plates approach each other, driving the two limit plates to move closer, and at the same time stretching the spring;

[0017] S2, insert the mutually approaching limit plates into the corresponding limit grooves on the second enclosure plate. When the limit plates lose pressure, the springs deform, converting the elastic potential energy into kinetic energy to react on the limit plates. At this time, the slider slides in the slide groove driven by the roller, driving the two moving plates away from each other and causing the two limit plates to move in opposite directions until they are inserted into the limit grooves.

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

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

[0020] S5. After the equipment has been running for a long period of time, the heat exchange efficiency becomes low and the plate holes become clogged due to the adhesion and precipitation of liquid impurities. The entire equipment should be quickly disassembled for cleaning.

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

[0022] In the present invention, when the absorbent hot lean liquid enters the liquid distributor from the distribution pipe, the absorbent lean liquid is distributed on the inner wall of the heat exchange plate through the liquid guide plate, and the vertical concave-convex structure evenly distributes the absorbent lean liquid to form a uniform liquid film. The absorbent lean liquid evaporates downward along the heat exchange plate, and the water vapor and the absorbent lean liquid are separated in countercurrent or parallel flow, thereby achieving uniform distribution of the lean liquid and enhancing the overall heat exchange performance. The two limit plates are limited to be close, and the spring is stretched at the same time, and the limit plates close to each other are inserted into the corresponding limit grooves on the second enclosure. When the limit plate loses the pressure, the spring is deformed, and the elastic potential energy is converted into kinetic energy to react on the limit plate. At this time, the slider slides in the slide groove driven by the roller, driving the two moving plates away from each other, and moving the two limit plates in opposite directions until they are inserted into the limit groove, completing the splicing of the first enclosure and the second enclosure, forming a combined liquid distributor, the overall structure is simple, easy to use, reducing the size of the boiler, and reducing equipment investment. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

[0028] Figure 6 is a schematic structural diagram of the first enclosure in the present invention;

[0029] Figure 7 for Figure 6 A schematic diagram of the structure enlargement in the middle;

[0030] Figure 8 It is a structural schematic diagram of the lubrication unit in the present invention;

[0031] Fig. 9 It is a heat exchange comparison diagram of a tubular falling film boiler and a compact falling film boiler of the present invention;

[0032] Fig.10 It is a heat exchange comparison diagram of a boiler without a vertical concave-convex structure and a falling film boiler with a vertical concave-convex structure of the present invention.

[0033] In the figure: 1. first enclosure; 2. second enclosure; 3. liquid guide plate; 4. through hole; 5. heat exchange plate; 6. groove; 7. spring; 8. movable plate; 9. limit plate; 10. slide groove; 11. slider; 12. connecting rod; 13. roller; 14. limit groove. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be pointed out that the embodiments described below are intended to facilitate the understanding of the present invention and do not have any limiting effect on the present invention.

[0035] like Figures 1 to 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 arranged 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 to achieve countercurrent or cocurrent separation of water vapor and the absorbent lean liquid. The two limit plates 9 are limited close to each other, and the spring 7 is stretched at the same time, and the limit plates 9 approaching each other are inserted into the corresponding limit grooves 14 on the second enclosure 2. When the limit plates 9 lose the pressure, the spring 7 is deformed, and the elastic potential energy is converted into kinetic energy to react on the limit plates 9. At this time, the slider 11 slides in the slide groove 10 driven by the roller 13, driving the two movable plates 8 away from each other and moving the two limit plates 9 in opposite directions until they are inserted into the limit grooves 14, completing the splicing of the first enclosure 1 and the second enclosure 2 to form a combined liquid distributor with a simple overall structure and convenient use. When the absorbent hot lean liquid enters the liquid distributor from the distribution pipe, the absorbent lean liquid is distributed on the inner wall of the heat exchange plate 5 through the liquid guide plate 3, and the absorbent lean liquid can evaporate downward along the heat exchange plate 5, and the water vapor and the absorbent lean liquid are separated in countercurrent or parallel flow, so as to facilitate the uniform distribution of the lean 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 circulation of absorbent lean liquid is reserved between each two heat exchange plates 5. Each heat exchange plate 5 is provided with a vertical concave-convex structure, which is 4 mm long, 3 mm wide, and 3 mm deep. Relying on the vertical concave-convex structure, the absorbent lean liquid is evenly distributed on the inner wall of the heat exchange plate 5.

[0037] In order to facilitate the rapid assembly of the first enclosure 1 and the second enclosure 2, the liquid distributor includes the first enclosure 1 and the second enclosure 2 and a plurality of liquid guide plates 3. The first enclosure 1 and the second enclosure 2 form an independent space for placing the liquid guide plates 3. A square groove for the circulation of the absorbent lean liquid is preset between each two liquid guide plates 3, and through holes 4 are linearly distributed on the surface of each liquid guide plate 3. The absorbent lean liquid circulates in the square groove and flows to the surface of the heat exchange plate 5 through the through holes 4. The independent space is convenient for installing the liquid guide plate 3. Multiple groups of plate-type heat exchange plates 5 are used to improve the heat exchange performance, and the heat exchange plates 5 correspond to the liquid guide plates 3 in the independent space. The first enclosure 1 and the second enclosure 2 are connected by a limiting mechanism to ensure the uniform distribution of the absorbent lean 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 enclosure 1 toward the second enclosure 2, and springs 7 are provided on the upper and lower sides of the groove 6. Through the stretching of the spring 7, the elastic potential energy is converted into kinetic energy, and the reaction moving plate 8 is used to facilitate the mutual approach and distance between the limiting plates 9, thereby realizing the splicing of the first enclosure 1 and the second enclosure 2.

[0038] There are two springs 7, and a moving plate 8 is provided at one end of the two springs 7 that are close to each other. The moving plate 8 is connected to a limiting plate 9 at one end away from the spring 7. The two limiting plates 9 are arranged oppositely to facilitate insertion into the limiting groove 14. Slide grooves 10 are provided on both the left and right sides of the groove 6, and sliders 11 are provided at both ends of the moving plate 8. A lubrication unit is provided at one end of the slider 11 extending into the slide groove 10.

[0039] like Figures 7-8 As shown, the lubrication unit includes a strip groove opened at one end of the slider 11 near the slide groove 10, and two connecting rods 12 and rollers 13 are arranged in the strip groove. The rollers 13 are arranged between the two connecting rods 12, and the rollers 13 are in contact with the slide groove 10. By rotating the rollers 13 and contacting with the slide groove 10, the rollers 13 can slide in the slide groove 10, driving the slider 11 to move, so that the moving plate 8 drives the limiting plate 9 to follow the movement. A limiting groove 14 adapted to the limiting plate 9 is opened on the side of the second enclosure 2 near the limiting plate 9, and the limiting plate 9 is inserted into the limiting groove 14 to complete the splicing of the first enclosure 1 and the second enclosure 2.

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

[0041] S1. First, the limit plate 9 is pressed, and the roller 13 slides in the slide groove 10, driving the slider 11 to move, so that the two movable plates 8 approach each other, driving the two limit plates 9 to limit and approach, and at the same time stretching the spring 7;

[0042] S2, insert the mutually approaching limiting plates 9 into the corresponding limiting grooves 14 on the second enclosure 2. When the limiting plates 9 lose the pressure, the spring 7 deforms, converts the elastic potential energy into kinetic energy to react on the limiting plates 9. At this time, the slider 11 slides in the slide groove 10 driven by the roller 13, drives the two movable 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.

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

[0044] S4. The absorbent lean liquid evaporates downward along the heat exchange plate 5, and the water vapor and the absorbent lean liquid are separated in countercurrent or cocurrent.

[0045] S5. After the equipment has been running for a long period of time, problems such as low heat exchange efficiency and blockage of plate holes caused by the adhesion and precipitation of liquid impurities can be solved by quickly disassembling the equipment for cleaning.

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

[0047] like Fig.10 As shown in the figure, in the heat exchange comparison between the boiler without vertical concave-convex structure and the falling film boiler with vertical concave-convex structure, 144℃, 0.3MPa steam is introduced to heat 25℃ water to 110℃. The heating time of the falling film boiler with vertical concave-convex structure is 10min, which is less than 12min of the tubular falling film boiler. It can be seen from the figure that the vertical concave-convex structure can enhance the heat exchange efficiency.

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

Claims

1. A compact falling film boiler for a carbon dioxide chemical absorption system, characterized in that: It includes a heat exchange core and a liquid distributor arranged on the upper surface of the heat exchange core; The liquid distributor comprises a first enclosing plate (1), a second enclosing plate (2) and a plurality of liquid guide plates (3), wherein the first enclosing plate (1) and the second enclosing plate (2) form an independent space for placing the liquid guide plates (3), a square groove for the circulation of absorbent lean liquid is preset between two adjacent liquid guide plates (3), and through holes (4) are linearly distributed on the surface of each liquid guide plate (3); The liquid distributor is used to make the absorbent lean liquid uniformly flow downward into the heat exchange core, and the absorbent lean liquid evaporates downward along the heat exchange core to achieve countercurrent or cocurrent separation of water vapor and absorbent lean liquid.

2. The compact falling film boiler of the carbon dioxide chemical absorption system according to claim 1, characterized in that: The first enclosure plate (1) and the second enclosure plate (2) are connected via a limiting mechanism.

3. The compact falling film boiler of the carbon dioxide chemical absorption system according to claim 2, characterized in that: The limiting mechanism comprises a groove (6) provided on the outer side of the first enclosure (1) towards the two ends of the second enclosure (2); springs (7) are provided on the upper and lower sides of the groove (6); a movable plate (8) is provided at the end close to the two springs (7); the end of the movable plate (8) away from the spring (7) is connected to the limiting plate (9); and a limiting groove (14) adapted to the limiting plate (9) is provided on the side of the second enclosure (2) close to the limiting plate (9).

4. The compact falling film boiler of the carbon dioxide chemical absorption system according to claim 3, characterized in that: The left and right sides of the groove (6) are provided with slide grooves (10), and both ends of the movable plate (8) are provided with sliders (11) that match the slide grooves (10), and one end of the slider (11) extending into the slide groove (10) is provided with a lubrication unit.

5. The compact falling film boiler of the carbon dioxide chemical absorption system according to claim 4, characterized in that: The lubrication unit comprises a strip groove opened at one end of the slider (11) close to the slide groove (10), a connecting rod (12) and a roller (13) are arranged in the strip groove, the roller (13) is arranged on the connecting rod (12), and the roller (13) is in contact with the slide groove (10).

6. The compact falling film boiler of the carbon dioxide chemical absorption system according to claim 1, characterized in that: The heat exchange core comprises a plurality of heat exchange plates (5), and a gap for the circulation of absorbent lean liquid is reserved between every two heat exchange plates (5).

7. The compact falling film boiler of the carbon dioxide chemical absorption system according to claim 6, characterized in that: The surface of each heat exchange plate (5) is provided with vertical concave-convex structures arranged in an array, and the absorption liquid and the lean liquid are evenly distributed on the inner wall of the heat exchange plate (5) by means of the vertical concave-convex structures.

8. The method for using the compact falling film boiler of the carbon dioxide chemical absorption system according to any one of claims 1 to 7, characterized in that: include: S1. First, the limit plate (9) is pressed, and the roller (13) slides in the slide groove (10), driving the slider (11) to move, so that the two movable plates (8) approach each other, driving the two limit plates (9) to limit and approach, and at the same time stretching the spring (7); S2, inserting the mutually approaching limiting plates (9) into the corresponding limiting grooves (14) on the second enclosure (2), when the limiting plates (9) lose the pressure, the spring (7) deforms, converting the elastic potential energy into kinetic energy to react on the limiting plates (9), at which time, the slider (11) slides in the slide groove (10) driven by the roller (13), driving the two movable plates (8) 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); S3, pouring the absorbent hot lean liquid into the distribution pipe, and flowing from the distribution pipe into the liquid distributor, the absorbent lean liquid is guided by the liquid guide plate (3), flows through the through hole (4) in the square groove, and is evenly 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 and the absorbent lean liquid are separated in countercurrent or cocurrent; S5. After the equipment has been running for a long period of time, the heat exchange efficiency becomes low and the plate holes become clogged due to the adhesion and precipitation of liquid impurities. The entire equipment should be quickly disassembled for cleaning.

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