Self-sustaining one-step purification equipment and purification process

Abstract

The present application discloses a self-sustaining one-step purification device and a purification process for purifying flue gas containing water vapor, ammonia, and acidic pollutants; the purification device includes a flue gas inlet and a flue gas outlet, as well as a flue gas purification channel from the flue gas inlet to the flue gas outlet; a low-temperature condensation module is arranged in the flue gas purification channel to cool and condense the flue gas entering the flue gas purification channel from the flue gas inlet, condense the water vapor into condensed water, and the ammonia and the acidic pollutants dissolve in the condensed water and undergo an acid-base neutralization reaction in the condensed water to form a non-volatile salt that is easily soluble in the condensed water. The present application can effectively solve the problem of ammonia escape.

Description

Technical Field

[0001] The present application relates to the technical field of environmental protection equipment. Specifically, it relates to a self-sustaining one-step purification equipment and a purification process. Background Art

[0002] At present, most of the cement kiln tail gas NOx treatment technologies still use ammonia source (such as ammonia water, urea, etc.) reducing agents. Due to the limitation of the denitrification rate, there are more or less problems of secondary air pollution caused by the phenomenon of ammonia escape due to the excessive use of reducing agents.

[0003] The known prior art discloses a recovery and circulation system for escaping ammonia in the tail gas of cement kiln ammonia denitrification and its control method. The system includes a spray tower, a heat exchanger, a storage tank, and a receiving tank. The denitrification tail gas in the flue is transported by a fan to the heat exchanger for cooling, and then enters the tower from the bottom of the spray tower; then the absorbent in the storage tank is pumped by a pump to the spray tower to contact and react with the upward denitrification tail gas to obtain ammonia-containing absorbent and ammonia-removed tail gas; after that, the ammonia-containing absorbent flows into the receiving tank, and after precipitation, the supernatant is pumped and recycled into the spray tower to contact the denitrification tail gas repeatedly until a saturated ammonia absorbent is formed; and the slurry settled at the bottom of the receiving tank is regularly pumped to the cement kiln by a pump; the saturated ammonia absorbent is pumped to an ammonia water storage tank and mixed with ammonia water for denitrification reaction. Ammonium salts decompose ammonia during the SNCR process as part of the ammonia source to react with nitrogen oxides, thereby realizing the recycling of escaping ammonia.

[0004] Although this prior art can solve the problem of ammonia escape, it has low ammonia removal efficiency, large equipment volume, and high cost. The specific analysis is as follows:

[0005] 1. The prior art needs to first heat exchange, then spray, then collect, and then recycle the tail gas treatment. The multiple treatment steps lead to a complex ammonia removal process and low ammonia removal efficiency.

[0006] 2. Before the tail gas of the prior art enters the spray tower, only limited cooling can be achieved through the heat exchanger. On the one hand, because high-temperature ammonia is easy to volatilize and is not conducive to being absorbed in the spray tower, cooling the high-temperature tail gas through the pre-positioned heat exchanger can improve the absorption efficiency of ammonia in the spray tower. On the other hand, the pre-cooling treatment through the heat exchanger can reduce the working pressure of the spray tower, that is, reduce the spray water volume of the spray tower. However, when using a spray tower to absorb ammonia, the spray water volume is still huge, which also results in a large receiving volume of the subsequent receiving tank of this prior art, a large equipment volume, and a large treatment volume for the ammonia-containing absorbent to be recycled into the spray tower.

[0007] 3. The ammonia-containing absorbent of the prior art needs a long time to precipitate when flowing into the receiving tank, which further leads to a reduction in the ammonia removal efficiency of this prior art.

[0008] Therefore, overall, the existing ammonia escape recovery and circulation system has problems such as complex processes, low ammonia removal efficiency, large equipment volume, high costs, and a large amount of wastewater treatment. Summary of the Invention

[0009] The main purpose of this application is to provide a self-sustaining one-step purification device and purification process to solve the problems of complex processes, low ammonia removal efficiency, large equipment volume, and high costs existing in the ammonia escape purification devices in related technologies.

[0010] To achieve the above objective, in the first aspect of this application, a self-sustaining one-step purification device is provided for purifying flue gas containing water vapor, ammonia, and acidic pollutants; the purification device includes:

[0011] A flue gas inlet and a flue gas outlet, as well as a flue gas purification channel from the flue gas inlet to the flue gas outlet;

[0012] A low-temperature condensation module, arranged in the flue gas purification channel, which cools and condenses the flue gas entering the flue gas purification channel from the flue gas inlet, condenses the water vapor into condensed water, and the ammonia and the acidic pollutants dissolve in the condensed water and undergo an acid-base neutralization reaction in the condensed water to form non-volatile salts that are easily soluble in the condensed water.

[0013] Optionally, the low-temperature condensation module is connected to a cooling water inlet and a cooling water return outlet; the low-temperature condensation module includes a cooling water pipe bundle vertically arranged and arranged in an array in the flue gas purification channel and end joint assemblies connected to the upper and lower ends of the cooling water pipe bundle, and the end joint assemblies together with the cooling water pipe bundle form a cooling water circulation pipeline for the cooling water to flow from the cooling water inlet to the cooling water return outlet.

[0014] Optionally, the cooling water pipe bundle is arranged in a staggered row tube bundle array.

[0015] Optionally, the cooling water pipe bundle is divided into several cooling water pipe areas along the flue gas flow direction, and each cooling water pipe area includes multiple rows of cooling water pipes arranged along the flue gas flow direction. The adjacent two rows of cooling water pipes among the multiple rows of cooling water pipes are staggered in the flue gas flow direction and there is no gap between their orthographic projection surfaces.

[0016] Optionally, the three cooling water pipes with the closest distance in the adjacent two rows of cooling water pipes form a cooling water pipe unit arranged in a triangle, and the arrangement dimension range of the cooling water pipe unit is:

[0017] C = 1.8A to 2A;

[0018] D = 0.8B to 1.5B;

[0019] Among them, A is the maximum width dimension of the pipe cross-section; B is the maximum length dimension of the pipe cross-section; C is the center distance dimension between the pipe cross-sections of two adjacent cooling water pipes in the same row; D is the center distance dimension between the pipe cross-sections of adjacent rows of cooling water pipes.

[0020] Optionally, the cooling water pipe is an arc-shaped rhombus cooling water pipe, and the arc-shaped rhombus cooling water pipe includes: a cooling water pipe body, the cross-section of the cooling water pipe body is in the shape of an arc-shaped rhombus, the two ends of its short diagonal are respectively large arc ends, and the two ends of the long diagonal are respectively small arc ends; the large arc ends at both ends of the short diagonal and the small arc ends at both ends of the long diagonal are respectively connected by straight edges, and the straight edges are tangent to the arc lines of the large arc ends and the small arc ends.

[0021] Optionally, the large arc ends at both ends of the short diagonal are concentrically arranged.

[0022] Optionally, the connection line of the midpoints of the large arc ends at both ends of the short diagonal is perpendicular to the connection line of the small arc ends at both ends of the long diagonal.

[0023] Optionally, both the large arc end and the small arc end include inner rounded corners and outer rounded corners.

[0024] Optionally, the applicable ranges of the dimensions of the cross-section of the cooling water pipe body are as follows:

[0025] A = 20 - 100 mm;

[0026] B = A - 2A;

[0027] R 1 = 1 / 2 × A;

[0028] R 2 = R 1 - t;

[0029] r 1 = 6 - 1 / 2 × R 1 ;

[0030] r 2 = r 1 - t;

[0031] Among them, A is the length of the short diagonal of the cooling water pipe body 1020; B is the length of the long diagonal of the cooling water pipe body 1020; R 1 is the outer diameter dimension of the large arc end; R 2 is the inner diameter dimension of the large arc end; t is the wall thickness of the cooling water pipe body 1020; r 1 is the outer diameter dimension of the small arc end; r 2 is the inner diameter dimension of the small arc end.

[0032] Optionally, the arc-rhombus cooling water pipe further includes an upper joint and a lower joint respectively arranged at two vertical ends of the cooling water pipe body; wherein, the upper joint and the lower joint have the same structure, and both include a plug and a joint. The plug is hermetically fixed at two vertical ends of the cooling water pipe body, and the first end of the joint is hermetically fixed on the plug and communicated with the inside of the cooling water pipe body, and the second end extends out of the plug.

[0033] Optionally, the cross-section of the plug is set to an arc-rhombus shape same as that of the cooling water pipe body, and a joint installation hole is axially formed in the plug; the first end of the joint is hermetically fixed in the joint installation hole.

[0034] Optionally, an annular groove is arranged in the joint installation hole, a sealing ring is embedded in the annular groove, and the joint is threadedly connected with the joint installation hole and presses the sealing ring tightly in the annular groove.

[0035] Optionally, the end joint assembly includes an upper end joint assembly and a lower end joint assembly. The upper end joint assembly and the lower end joint assembly are alternately arranged in sequence above and below the cooling water pipe bundle along the flue gas flow direction, and each end joint penetrates through the ends of multiple rows of cooling water pipes to form a parallel pipeline in the cooling water pipe bundle for at least two rows of parallel water flows to flow in the same direction.

[0036] Optionally, the upper end joint assembly is an upper water tank, and the lower end joint assembly is a lower water tank. The upper water tank includes multiple upper water tank sub-parts arranged along the flue gas flow direction above the cooling water pipe bundle as the end joints, and the lower water tank includes multiple lower water tank sub-parts arranged along the flue gas flow direction below the cooling water pipe bundle as the end joints. The multiple rows of cooling water pipes penetrated by each water tank sub-part include an inlet water pipeline and an outlet water pipeline arranged side by side along the flue gas flow direction, and the number of rows of the inlet water pipeline and the outlet water pipeline is the same.

[0037] Optionally, one of the upper water tank and the lower water tank further includes a cooling water inlet tank communicated with the cooling water inlet, and the other further includes a cooling water return tank communicated with the cooling water return port. Both the cooling water inlet tank and the cooling water return tank correspondingly penetrate through at least two rows of cooling water pipes.

[0038] Optionally, the cooling water pipe bundle is divided into multiple cooling water pipe areas along the flue gas flow direction. Each cooling water pipe area includes multiple rows of cooling water pipes arranged along the flue gas flow direction, and each cooling water pipe area correspondingly communicates with a group of the cooling water inlets and the cooling water return ports. The cooling water flows between multiple cooling water pipe areas are not communicated in the cooling water pipe bundle.

[0039] Optionally, the cooling water flow rate in the cooling water pipe area near the flue gas outlet is less than that in the cooling water pipe area near the flue gas inlet.

[0040] Optionally, the cooling water pipe area is provided with three sections, and the cooling water flow rate in the cooling water pipe area decreases sequentially along the flue gas flow direction.

[0041] Optionally, it further includes a main cooling water inlet pipe, and the main cooling water inlet pipe is communicated with each of the cooling water inlets through a flow regulating valve.

[0042] Optionally, the upper end joint assembly is an upper water tank that penetrates the upper ends of all the cooling water pipes, and the lower end joint assembly is a lower water tank that penetrates the lower ends of all the cooling water pipes. One of the upper water tank and the lower water tank is communicated with the cooling water inlet, and the other is communicated with the cooling water return port.

[0043] Optionally, the cooling water flow rate in the cooling water pipe area from the flue gas inlet to the flue gas outlet decreases sequentially.

[0044] Optionally, the upper end joint assembly is an upper water tank that penetrates the upper ends of all the cooling water pipes, and the lower end joint assembly is a lower water tank. The lower water tank includes a plurality of lower water tank sub - sections arranged along the flue gas flow direction, and each lower water tank sub - section penetrates multiple rows of the cooling water pipes; the upper water tank is communicated with a cooling water return port, and each lower water tank sub - section is communicated with a cooling water inlet.

[0045] Optionally, it further includes a main cooling water inlet pipe, and the main cooling water inlet pipe is communicated with each of the cooling water inlets through a flow regulating valve.

[0046] Optionally, the end joint assembly is a circular pipe elbow assembly that sequentially communicates the ends of two adjacent cooling water pipes.

[0047] Optionally, the cooling water pipe bundle is divided into several cooling water pipe areas along the flue gas flow direction. Each cooling water pipe area includes multiple rows of cooling water pipes arranged along the flue gas flow direction; each cooling water pipe area is communicated with a collecting pipe and a return pipe.

[0048] Optionally, it further includes a box body, and the two sides of the box body are provided with the flue gas inlet and the flue gas outlet; water pipe installation holes for installing the upper end and the lower end of the cooling water pipe bundle are formed on the upper box plate and the lower box plate of the box body, and an annular groove is formed on the inner wall of the water pipe installation hole along its circumferential direction; the end of the cooling water pipe is arranged in the water pipe installation hole, and a part of the cooling water pipe body corresponding to the annular groove is provided with an annular protrusion, and the annular protrusion is hermetically embedded in the annular groove so that the end of the cooling water pipe body forms a curved surface seal with the water pipe installation hole.

[0049] Optionally, sealant is provided in the annular groove.

[0050] Optionally, the annular groove is coaxially arranged with the water pipe installation hole.

[0051] Optionally, a rubber gasket is further provided in the annular groove, and the annular protrusion presses the rubber gasket tightly in the annular groove.

[0052] Optionally, the annular groove includes a plurality of grooves arranged at intervals along the circumferential direction of the inner wall of the water pipe installation hole, and the extending depths of the plurality of grooves on the inner wall are the same or different.

[0053] Optionally, a plurality of annular grooves are provided and distributed along the axial direction of the water pipe installation hole.

[0054] Optionally, two annular grooves are provided, including a first annular groove and a second annular groove, and the groove opening directions of the first annular groove and the second annular groove are inclined in opposite directions along the axial direction of the water pipe installation hole; correspondingly, the annular protrusions include a first annular protrusion and a second annular protrusion, and the protrusion directions of the first annular protrusion and the second annular protrusion are inclined in opposite directions along the axial direction of the water pipe installation hole.

[0055] Optionally, two annular clamping protrusions are further provided on the cooling water pipe body, the two annular clamping protrusions are located inside and outside the installation base, and the opposite surfaces of the two annular clamping protrusions are respectively pressed against the inner side surface and the outer side surface of the installation base.

[0056] Optionally, a plurality of demisting, water collecting and water blocking plates are vertically arranged at the flue gas outlet, and the plate surface of the demisting, water collecting and water blocking plates is a corrugated surface.

[0057] Optionally, at least part of the demisting, water collecting and water blocking plates are formed with oblong holes extending vertically along the surface of the demisting, water collecting and water blocking plates.

[0058] Optionally, a wire mesh is further provided on the outer side of the demisting, water collecting and water blocking plates.

[0059] Optionally, the flue gas temperature at the flue gas inlet is 70°C - 170°C, the moisture content of the flue gas is 5% - 10%, and the escaped ammonia is 9 mg / m 3 -200 mg / m 3 , the water temperature at the inlet of the cooling water is 26°C - 32°C, and the SO 2 content is 5 mg / m 3 -100 mg / m 3 , the NOx content is 30 mg / m 3 -60 mg / m 3 , the CO 2 concentration is 18% - 22%, and the dust content is 5 mg / m 3 -15 mg / m 3 ;

[0060] The flue gas temperature at the flue gas outlet is 30°C - 50°C, the water content of the flue gas is 3% - 6%, and the escaped ammonia is 0 mg / m 3 -7 mg / m 3 .

[0061] Optionally, it further includes an atomizing device, which is arranged at the flue gas inlet and sprays atomized water towards this place to increase the water content in the flue gas.

[0062] Optionally, a medicament for ammonia removal and / or desulfurization and / or denitration is added to the atomized water of the atomizing device.

[0063] Optionally, it further includes a spray cleaning device, which is arranged at the flue gas inlet and is used to spray cleaning water into the flue gas. The cleaning water flushes the surface of the cooling water pipe of the low-temperature condensation module along with the flue gas to wash away the particulate matter adhered to the pipe surface.

[0064] Optionally, the box body includes an upper box plate, a lower box plate, a front box plate and a rear box plate. The upper box plate is hermetically connected to the front box plate and the rear box plate, and the lower box plate is hermetically connected to the front box plate and the rear box plate, jointly forming the upper, lower, front and rear seals of the low-temperature condensation module. The left and right directions of the purification equipment are the flue gas inlet and the flue gas outlet.

[0065] Optionally, it further includes a condensate collection device arranged at the bottom of the low-temperature condensation module for collecting the condensate, and the condensate collection device is connected to the condensate discharge port.

[0066] Optionally, the acidic pollutants include at least one of sulfur dioxide, carbon dioxide, and NOx.

[0067] The second aspect of this application also provides a purification process for the above self-sustaining one-step purification equipment, including the following steps:

[0068] Install the self-sustaining one-step purification equipment at the flue gas outlet of the flue gas emission equipment to be purified, and seal the flue gas inlet of the self-sustaining one-step purification equipment with the flue gas outlet of the flue gas emission equipment to be purified;

[0069] Start the self-sustaining one-step purification equipment to work. By cooling the flue gas, the water vapor in the flue gas is condensed into condensed water, and the ammonia gas and acidic pollutants contained in the flue gas dissolve in the condensed water to undergo an acid-base neutralization reaction to generate non-volatile salts that are easily soluble in the condensed water. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The drawings forming a part of this application are used to provide a further understanding of this application, making other features, objectives, and advantages of this application more obvious. The schematic embodiments and descriptions of the drawings of this application are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0071] Figure 1A is a schematic diagram of the self-sustaining one-step purification process flow of an embodiment of this application;

[0072] Figure 1B is a schematic structural diagram (front view) of the self-sustaining one-step purification equipment of an embodiment of this application;

[0073] Figure 1C is Figure 1B the top view of;

[0074] Figure 1D is a structural diagram (front view) of the self-sustaining one-step purification equipment of an embodiment of this application;

[0075] Figure 1E is Figure 1D the side view of;

[0076] Figure 2A is a schematic structural diagram (front view) of the self-sustaining one-step purification equipment (round tube) of an embodiment of this application;

[0077] Figure 2B is Figure 2A the top view of;

[0078] Figure 2C is a structural diagram (front view) of the self-sustaining one-step purification equipment (round tube grouping) of an embodiment of this application;

[0079] Figure 2D is Figure 2C the top view of;

[0080] Figure 2E is a three-dimensional view of the self-sustaining one-step purification equipment (round tube grouping) of an embodiment of this application;

[0081] Figure 3A is the front view of the low-temperature condensation module (cooling water circulates along grouped water pipes) according to an embodiment of the present application;

[0082] Figure 3B is Figure 3A the top view of;

[0083] Figure 3C is Figure 3A the left view of;

[0084] Figure 3D is the three-dimensional sectional view of the low-temperature condensation module (cooling water circulates along grouped water pipes) according to an embodiment of the present application;

[0085] Figure 4A is the front view of the low-temperature condensation module (cooling water in each area circulates directly along grouped water pipes and the cooling water volume is adjustable) according to an embodiment of the present application;

[0086] Figure 4B is Figure 4A the top view of;

[0087] Figure 4C is the left view of the low-temperature condensation module (cooling water in each area circulates directly along grouped water pipes and the cooling water volume is adjustable) according to an embodiment of the present application;

[0088] Figure 5A is the front view of the low-temperature condensation module (cooling water in each area is adjustable) according to an embodiment of the present application;

[0089] Figure 5B is Figure 5A the top view of;

[0090] Figure 5C is Figure 5A the left view of;

[0091] Figure 6A is the front view of the low-temperature condensation module (cooling water in each area circulates directly along grouped water pipes and the cooling water volume is adjustable) according to an embodiment of the present application;

[0092] Figure 6B is Figure 6A the top view of;

[0093] Figure 6C is Figure 6A the left view of;

[0094] Figure 6D is the three-dimensional sectional view of the low-temperature condensation module (cooling water in each area circulates directly along grouped water pipes and the cooling water volume is adjustable) according to an embodiment of the present application;

[0095] Figure 7A is the top view of the arc-shaped rhombic tube according to an embodiment of the present application;

[0096] Figure 7B It is the front view of the arc-rhombus tube in the embodiment of the present application;

[0097] Figure 7C It is the cross-sectional view of the arc-rhombus tube in the embodiment of the present application;

[0098] Figure 8 It is the arrangement diagram of the arc-rhombus tubes in the embodiment of the present application;

[0099] Figure 9A It is the front view of the arc-rhombus tube before tube expansion in the embodiment of the present application;

[0100] Figure 9B It is Figure 9A the partial enlarged view of;

[0101] Figure 10A It is the front view of the arc-rhombus tube after tube expansion in the embodiment of the present application;

[0102] Figure 10B It is Figure 10A the partial enlarged view of;

[0103] Figure 10C It is Figure 10A the top view of;

[0104] Figure 11A It is the front view of the modular self-sustaining one-step purification equipment in the embodiment of the present application;

[0105] Figure 11B It is the top view of the modular self-sustaining one-step purification equipment in the embodiment of the present application;

[0106] Figure 11C It is the left view of the modular self-sustaining one-step purification equipment in the embodiment of the present application;

[0107] Figure 12 It is the structural schematic diagram of the demisting, water collecting and water blocking plate in the embodiment of the present application;

[0108] Figure 13 It is the simplified schematic diagram of convective heat transfer of the low-temperature condensation module in the embodiment of the present application.

[0109] Among them, 1 is a low-temperature condensation module, 101 is a box body, 1011 is an upper box plate, 1012 is a lower box plate, 1013 is a front box plate, 1014 is a rear box plate, 102 is a cooling water pipe bundle, 102a is a cooling water pipe, 1020 is a cooling water pipe body, 1020b is a large arc end, 1020a is a small arc end, 1020c is a straight edge, 1022 is a plug, 103 is a cooling water inlet pipe, 1031 is a flow regulating valve, 1032 is a cooling water inlet main pipe, 1033 is a branch pipe, 104 is a cooling water return pipe, 105 is a round pipe elbow, 2 is a spraying device, 3 is an atomizing device, 4 is a flue gas inlet, 5 is a flue gas outlet, 9 is a water pump, 10 is a condensate discharge port, 11 is an upper water tank, 111 is an upper water tank section, 12 is a lower water tank, 121 is a lower water tank section, 13 is a demisting, water collecting and water blocking plate, 14 is a wire mesh, 15 is a rubber gasket, 16 is a sealant, 17 is an annular groove, 18 is an annular protrusion, 19 is an annular clamping protrusion, 20 is an installation foundation, 21 is a lower joint, 211 is a plug, 212 is a sealing ring, 213 is a joint, 22 is an upper joint, 23 is a condensate collecting device, 24 is a cooling water pipe area, 103a is a cooling water inlet, 104a is a cooling water return port, 102b is a water pipe installation hole. Detailed implementation manner

[0110] In order to enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0111] It should be noted that the terms "first", "second", etc. in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to implement the embodiments of this application described here.

[0112] In this application, the orientation or positional relationship indicated by the terms "upper", "lower", "inner", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe this application and its embodiments, and are not used to limit that the indicated device, element or component must have a specific orientation, or be constructed and operated in a specific orientation.

[0113] Moreover, in addition to being able to represent an orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0114] In addition, terms such as "arranged", "provided with", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there can be internal communication between two devices, components or parts. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0115] In addition, the meaning of the term "plurality" should be two or more.

[0116] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the drawings and combine with embodiments to detail this application.

[0117] Currently, for the treatment of high-temperature flue gas, such as the NOx treatment technology for cement kiln flue gas, the vast majority still uses ammonia source (such as ammonia water, urea, etc.) reducing agents. Due to the limitation of the denitrification rate, there is more or less the phenomenon of ammonia escape caused by the excessive use of reducing agents, which leads to secondary air pollution.

[0118] The known prior art discloses a recovery and circulation system for escaped ammonia in cement kiln ammonia-based denitrification flue gas and its control method. The recovery and circulation system includes a spray tower, a heat exchanger, a storage tank, and a receiving tank. The denitrified flue gas is first transported by a fan to the heat exchanger for cooling, then enters the tower from the bottom of the spray tower, and then the absorbent in the storage tank is pumped to the spray tower by a pump to contact and react with the upward denitrified flue gas, obtaining ammonia-containing absorbent and ammonia-removed flue gas. After that, the ammonia-containing absorbent flows into the receiving tank, and after precipitation, the supernatant is pumped and recycled into the spray tower to contact the denitrified flue gas repeatedly until a saturated ammonia absorbent is formed. The slurry settled at the bottom of the receiving tank is regularly pumped to the cement kiln by a pump, and the saturated ammonia absorbent is pumped to the ammonia water storage tank and mixed with ammonia water for denitrification reaction. Ammonium salts decompose ammonia during the SNCR (selective non-catalytic reduction) denitrification process as part of the ammonia source to react with nitrogen oxides, thereby realizing the recycling of escaped ammonia.

[0119] Although this prior art can solve the problem of ammonia escape, it has the defects of low ammonia removal efficiency, large equipment volume, and high cost. The specific analysis is as follows:

[0120] 1. This prior art needs to first exchange heat, then spray, then collect, and then recycle the flue gas treatment. The multiple treatment steps lead to a complex ammonia removal process and low ammonia removal efficiency. And due to the complex process, heat exchangers, spray towers, storage tanks, receiving tanks, etc. are required, resulting in a large overall ammonia removal equipment volume and high cost.

[0121] 2. The prior art discloses that the flue gas is first transported to a heat exchanger for cooling. However, from the understanding of the entire technical solution disclosed in the prior art, it can be concluded that the purpose of using a pre - placed heat exchanger to cool the flue gas in the prior art is, on the one hand, to avoid the situation that volatile high - temperature ammonia is not easily absorbed by the absorbent in the subsequent spray tower process. By performing limited cooling of the high - temperature flue gas through the pre - placed heat exchanger, the absorption efficiency of ammonia in the spray tower can be improved. On the other hand, the pre - cooling of high - temperature ammonia through the heat exchanger can reduce the working pressure of the spray tower. However, the prior art still uses a spray tower, indicating that the means for solving the ammonia escape problem in the prior art is still the traditional idea of ammonia absorption in the spray tower. Using a spray tower has problems such as a large amount of spray water and a large amount of subsequent sewage purification and treatment.

[0122] 3. The ammonia - containing absorbent flowing into the receiving tank requires a long time for precipitation, which further leads to low ammonia removal efficiency in the prior art.

[0123] Therefore, overall, the existing technology's ammonia escape recovery and circulation system has problems such as complex processes, low ammonia removal efficiency, large equipment volume, high cost, and a large amount of wastewater treatment.

[0124] To solve the problems of ammonia escape and the complex processes, low ammonia removal efficiency, large equipment volume, high cost, and large amount of wastewater treatment in the above - mentioned known prior art, this application proposes a self - contained one - step purification device and purification method that can complete physical and chemical reactions by itself to achieve ammonia absorption (self - sustaining type), with a small equipment volume (compact type), simple process (one - step method), low cost, and a small amount of wastewater treatment for the components in the flue gas to be treated. The purification device provided in this application can be applied not only to the cement kiln flue gas purification scenario but also to scenarios such as power plant or coal yard flue gas purification. However, it should be noted that the purification device provided in this application can only be applied to the purification treatment of flue gas containing water vapor, ammonia, and acidic pollutants.

[0125] As a preferred embodiment of this application, the purification device is applied to the purification of cement kiln ammonia - based denitrification flue gas. Currently, ammonia escape generally exists in cement kiln flue gas, and the flue gas emitted by the cement kiln is high - temperature, containing water vapor, ammonia, and acidic pollutants.

[0126] The purification device of this embodiment has a flue gas inlet 4, a flue gas outlet 5, and a flue gas purification channel from the flue gas inlet 4 to the flue gas outlet 5. The purification device further includes a low - temperature condensation module 1, and the low - temperature condensation module 1 is arranged in the flue gas purification channel.

[0127] The main structure of the above - mentioned purification device can achieve the purification treatment of cement kiln flue gas, and its purification principle is as follows:

[0128] The flue gas from the cement kiln enters the flue gas purification channel through the flue gas inlet 4 of the purification device. The low-temperature condensation module 1 in the flue gas purification channel cools and condenses the incoming flue gas, cooling the water vapor in the flue gas to condense it into condensed water (ideally, it is desired to condense all the water vapor into condensed water). The ammonia and acidic pollutants (such as SO2 and CO2) contained in the flue gas dissolve in the condensed water (physical purification). This is the first layer of purification achieved by the purification device of this application. However, due to the high temperature of the flue gas, the ammonia or acidic pollutants dissolved in the condensed water are likely to volatilize from the condensed water. But the innovation of the purification device of this application is that at the same time, the ammonia and acidic pollutants dissolve in the condensed water to undergo an acid-base neutralization reaction (chemical purification) to generate non-volatile salts that are easily soluble in the condensed water.

[0129] There can be various types of low-temperature condensation modules 1 in the purification device of this application, such as oil-immersed self-cooled low-temperature condensation, refrigerated low-temperature condensation, etc. As a preferred embodiment of this application, the low-temperature condensation module 1 adopts water-cooled low-temperature condensation. The purification device is provided with a cooling water inlet 103a and a cooling water return port 104a, and the low-temperature condensation module 1 is connected to the cooling water inlet 103a and the cooling water return port 104a. The low-temperature condensation module 1 includes a cooling water pipe bundle 102 vertically arranged and arranged in an array in the flue gas purification channel, and an end joint assembly connected to the upper and lower ends of the cooling water pipe bundle 102. The end joint assembly and the cooling water pipe bundle 102 together form a cooling water circulation pipeline for the cooling water to flow from the cooling water inlet to the cooling water return port.

[0130] After the flue gas enters the flue gas purification channel from the flue gas inlet 4, it comes into full contact with the surface of the cooling water pipe bundle 102 flowing with cooling water. The water vapor in the flue gas condenses into condensed water on the surface of the water pipes of the cooling water pipe bundle 102 and flows down along the surface of the cooling water pipes to the bottom of the purification device. Since the cooling water in this application does not come into direct contact with the flue gas, the cooling water in the cooling water pipe bundle 102 is not polluted and is continuously recycled after being cooled. Moreover, through calculation, the consumption of the cooling water in the cooling water pipe bundle 102 is much less than the water consumption in the spray tower in the prior art, and the condensed water purified and recycled by this purification device can fully make up for the evaporated water volume during the cooling process of the cooling water.

[0131] Figure 1BThe working principle of the purification equipment of the present application is shown. The purification equipment of the present application can be used in conjunction with a water pump 9, a cooling water circulation pipeline, and a cooling tower. The water pump 9 provides driving force for the cooling water entering from the cooling water inlet 103a through the cooling water inlet pipeline 103 of the cooling water circulation pipeline. The cooling water flows in the cooling water circulation pipeline and then flows out from the cooling water outlet 104a into the cooling tower, and the water in the cooling tower then flows back to the water pump 9 to achieve cooling water circulation. The flue gas of the cement kiln enters the interior of the low-temperature condensation module 1 through the flue gas inlet 4 of the low-temperature condensation module 1 and exchanges heat fully with the cooling water tube bundle 102. The cooling water tube bundle 102 quickly cools the flue gas. Importantly, the cooling water tube bundle 102 condenses the water vapor in the high-temperature flue gas into condensed water, and the condensed water adsorbs the alkaline ammonia molecules (ammonia gas), cement raw material dust (calcium-containing), and the acidic SO 2 and CO 2 and other gases in the flue gas. The alkaline ammonia molecules and cement raw material dust react with the acidic SO 2 and CO 2 in the condensed water to undergo an acid-base neutralization reaction to form non-volatile salts such as ammonium bisulfate, ammonium bicarbonate, calcium sulfate, and calcium carbonate.

[0132] The purification equipment of the present application further includes a condensed water collection device 23, which is arranged at the bottom of the low-temperature condensation module 1. The condensed water collection device 23 is connected to the condensed water discharge port 10. The condensed water generated on the surface of the cooling water tube bundle 102 flows down the surface of the water pipe to the bottom of the purification equipment, and then is collected by the condensed water collection device 23. Finally, the condensed water discharge port 10 discharges the condensed water externally.

[0133] Furthermore, the externally discharged condensed water can be treated by the membrane separation method into reusable or externally discharged purified water (about 90%) and about 10% of high-concentration water containing salts (the salt dust content is less than 3%). The high-concentration water containing salts is pumped and sprayed onto the clinker grate cooler at the kiln head of the cement kiln. On the one hand, it can quickly cool the clinker. On the other hand, substances such as calcium sulfate and calcium carbonate in the water adhere to the surface of the clinker and are taken out as components of the cement. The ammonium salts in the water are quickly heated and decomposed into ammonia and SO 2 and then enter the decomposition furnace of the cement kiln along with the tertiary air. Among them, the ammonia molecules play a denitrification function and are utilized in the decomposition furnace, and SO 2 reacts with CaO to form calcium sulfate and enters the clinker. The whole process has no secondary pollution, and all substances are recycled.

[0134] In the prior art known above, although it also discloses using a heat exchanger to cool the denitrified flue gas, the role of its heat exchanger in the above prior art is completely different from the role of the low-temperature condensation module 1 in the present application. The specific differences are as follows:

[0135] 1. Different inventive concepts

[0136] The above-mentioned prior art mainly removes ammonia by spraying absorbent in a spray tower, and the purpose of setting the heat exchanger is to reduce the load of the spray tower; the present application utilizes the fact that cement kiln flue gas contains water vapor, and the low-temperature condensation module 1 cools down the water vapor in the high-temperature flue gas and condenses it into condensed water, ammonia and SO 2 , CO 2 Acidic gases such as SO2 are easily dissolved in condensed water under the low temperature environment of the low temperature condensation module 1 (physical process). At the same time, alkaline ammonia molecules and acidic SO 2 With CO 2 Neutral acidic and alkaline substances undergo a neutralization reaction to form non-volatile substances such as ammonium bisulfate, ammonium bicarbonate, calcium sulfate and calcium carbonate (chemical process), which are discharged with the condensed water, so that the problem of ammonia escape in the cement kiln is effectively solved; the present application directly undergoes a deamination reaction in the heat exchanger without the need to add any absorbent.

[0137] 2. The role played by the heat exchanger in the prior art is objectively different from that of the low-temperature condensation module 1 of the present application.

[0138] 1) Although the prior art records that the heat exchanger can cool the flue gas to 50 degrees, it does not disclose that deamination is performed in the heat exchanger. From the full text of the prior art, the heat exchanger has no deamination effect. This is because, based on the inventive concept, the denitrified flue gas after cooling by the heat exchanger enters the spray tower, and the spray tower absorbs ammonia by spraying absorbent. For designers, it is not intentional to divide the ammonia absorption into two steps, that is, ammonia absorption in the heat exchanger part and ammonia absorption in the subsequent spray tower, which will only increase the difficulty of ammonia recovery;

[0139] 2) Based on the inventive concept of the prior art, the heat exchanger does not need to play a deamination role, because deamination is still required by spraying absorbent. If the heat exchanger can achieve deamination, there is no need for spray tower treatment.

[0140] 3) It is very important that for traditional heat exchangers, the general goal is to avoid generating condensed water as much as possible during the heat exchange process, because condensed water will corrode the pipes of the heat exchanger over a long period of time, resulting in a reduction in the service life of the heat exchanger. Therefore, it can be concluded that the heat exchanger of the prior art is not intended to generate condensed water.

[0141] 3. The above-mentioned known prior art has many defects

[0142] 1) There is a risk of absorbent escape. The ammonia absorbent used is formic acid. The volatilization and escape of the absorbent also require further treatment, and formic acid is also a flammable substance;

[0143] 2) The amount of wastewater treated after the absorbent absorbs ammonia is large, and the treatment cost is high;

[0144] 3) Since the method of spraying absorbent cannot fully utilize the absorbent, in order to improve the utilization rate of the absorbent, the absorbent has to be recycled. Not only does it require a long precipitation period, but the reflux pipeline used for the period of recycling will also suffer from severe corrosion, making the solution difficult to implement;

[0145] 4) It is difficult to detect whether the absorbent is saturated, and ineffective absorption is likely to occur, causing ammonia escape.

[0146] The purification equipment of the present application is different from the heat exchanger of the prior art, because the application scenario of the purification equipment of the present application is limited to the purification of flue gas containing water vapor, ammonia and acidic pollutants, and the pursuit of more condensed water in the cooling process to achieve physical and chemical purification is completely different from the concept of the existing heat exchanger. In addition, the purification equipment of the present application realizes self-sustaining, one-step deamination, and has the advantages of simple deamination process, small equipment size and low cost.

[0147] In addition, the purification equipment of the present application is not only suitable for deamination, because in the condensed water produced by the low-temperature condensation module 1, the alkaline ammonia gas, cement raw material dust and the acidic SO in the flue gas 2 , CO 2 , NOx and other acidic and alkaline substances undergo neutralization reactions, so the purification equipment in this application can also be used to remove SO 2 , CO removal 2 and deNOx.

[0148] The cooling water tube bundle 102 of the low temperature condensation module 1 of the present application is arranged in a staggered tube bundle array. Specifically, Figure 2B As shown, the cooling water tube bundle 102 includes multiple rows of cooling water tubes 102a arranged along the smoke flow direction, and two adjacent rows of cooling water tubes 102a are staggered in the smoke flow direction and have no gap between the orthographic projection surfaces in the smoke flow direction.

[0149] As a preferred embodiment of the present application, the orthographic projection surfaces of two adjacent rows of cooling water pipes 102a in the multiple rows of cooling water pipes 102a in the direction of the flue gas flow intersect. This arrangement allows the flue gas entering the flue gas purification channel to zigzag through the gaps of the cooling water pipe bundle 102, thereby increasing the heat exchange contact area between the flue gas and the cooling water pipe bundle 102 as much as possible, and ensuring that the normal flow of the flue gas does not affect the purification of the continuously incoming flue gas.

[0150] As a variation of the arrangement of the cooling water pipe bundle 102, in other embodiments, the boundaries of the front projections of two adjacent rows of the multi-row cooling water pipes 102a in the flue gas flow direction coincide. That is, the maximum width dimension of a cooling water pipe 102a in the previous row is exactly equal to the gap width between two adjacent cooling water pipes 102a in the subsequent row. This setting method can also avoid the situation where some flue gas directly passes through the gap existing between two adjacent rows of cooling water pipes 102a in the front-back direction without contacting the surface of the cooling water pipes 102a for heat exchange.

[0151] In the present application, the cooling water pipe 102a can be in the shape of a circular pipe, an elliptical pipe, a rectangular pipe, a rhombic pipe, etc. However, considering how to minimize the resistance encountered by the flue gas in the cooling water pipe bundle 102, maximize the heat exchange contact area between the flue gas and the cooling water pipe bundle 102, and maximize the heat exchange efficiency between the cooling water pipe 102 and the flue gas, it is necessary to conduct a refined design on the shape of the cooling water pipe 102.

[0152] For this reason, as a preferred embodiment of the present application, an arc rhombic cooling water pipe is proposed, as Figures 7A - 7C shown. The arc rhombic cooling water pipe includes: a cooling water pipe body 1020, the cross-section of the cooling water pipe body 1020 is in the shape of an arc rhombus, and the two ends of the short diagonal of the cross-section of the cooling water pipe body 1020 are respectively large arc ends 1020b, and the two ends of the long diagonal are respectively small arc ends 1020a;

[0153] The large arc ends 1020b at the two ends of the short diagonal and the small arc ends 1020a at the two ends of the long diagonal are respectively connected by straight edges 1020c, and the straight edges 1020c are tangent to the arc lines of the large arc ends 1020b.

[0154] As Figures 7A - 7C shown, the radius of curvature of the large arc end 1020b is much larger than that of the small arc end 1020a, that is, the curvature of the large arc end 1020b is much smaller than that of the small arc end 1020a. Due to the large curvature of the small arc end 1020a, an acute angle is formed together with the two straight edges 1020c.

[0155] The cooling water pipe body 1020 has a long strip structure, and its interior is a hollow structure for the flow of cooling water. When the cooling water pipe 102a is applied to a low-temperature condensation device, the small arc ends 1020a of the cooling water pipe body 1020 are horizontally arranged along the flue gas inlet 4 to the flue gas outlet 5 direction, that is, horizontally arranged along the left-right direction of the low-temperature condensation device, and the midpoint connection line of the two large arc ends 1020b is perpendicular to the connection line of the two small arc ends 1020a, that is, the two large arc ends 1020b are horizontally arranged along the front-back direction of the low-temperature condensation device.

[0156] In the embodiments of the present application, the cooling water pipe body 1020 with a cross-section in the shape of an arc rhombus is defined as an arc rhombus pipe. Compared with cooling water pipes with circular, elliptical, rhombus-shaped cross-sections, etc., it can achieve a larger heat exchange contact area between the flue gas and the cooling water pipe and a smaller flue gas resistance. The specific analysis is as follows:

[0157] Comparison with a circular pipe:

[0158] The length of the short diagonal of the arc rhombus pipe is the same as the diameter of the original circular cooling water pipe, while the length of the long diagonal is greater than the diameter of the original circular cooling water pipe. This makes the surface area at both ends of the improved arc rhombus pipe larger than that of the original circular cooling water pipe, thereby increasing the contact area between the cooling water pipe and the cement kiln flue gas, that is, increasing the heat exchange area.

[0159] In addition, since the curvature radius of the small arc end 1020a of the cooling water pipe body 1020 is much smaller than that of the large arc end, that is, the two ends of the cooling water pipe body 1020 are acute angles with a smaller included angle. Compared with the shape of the two ends of the circular cooling water pipe, the wind resistance at both ends of the arc rhombus-shaped cooling water pipe body 1020 is smaller. Therefore, the arc rhombus achieves resistance reduction compared with the circle.

[0160] Comparison with an elliptical pipe:

[0161] The arc rhombus pipe has two differences compared with the elliptical pipe. The first difference is that in the cooling water pipe body 1020 of the present application, the large arc end 1020b and the small arc end 1020a are connected by a straight edge 1020c, while the elliptical pipe is connected by an arc edge. When two cooling water pipes 102a are arranged in a staggered manner, the flow space formed between the two elliptical pipes is a structure with larger ends and a smaller middle, while the flow space formed between the two arc rhombus pipes is more flat in size. Therefore, it is more conducive to the flow of the tail gas and can avoid the influence on the flow of the tail gas caused by the change in the size of the flow space.

[0162] The second difference is that in order to form an arc rhombus structure in the present application, when the size of the large arc end 1020b with a large curvature radius is unified, the curvature radius of the other small arc end 1020a of the elliptical pipe is necessarily larger than that of the arc rhombus pipe. Therefore, the arc rhombus pipe has a smaller wind resistance at both ends compared with the elliptical pipe, and the technical effect of resistance reduction can also be achieved.

[0163] Comparison with a conventional rhombus pipe:

[0164] Compared with a diamond-shaped tube, the cross-sectional shape of the arc diamond-shaped tube is equivalent to replacing the upper and lower pointed ends of the diamond-shaped tube cross-section with large arc ends 1020b with a small curvature, and replacing the left and right pointed corners with small arc ends with a large curvature. The upper and lower ends of the arc diamond-shaped tube are large arc ends 1020b. Compared with the upper and lower ends of the diamond-shaped tube being obtuse ends, the use of an arc transition can make the flow of flue gas more stable. In addition, replacing the left and right pointed corners with small arc ends with a large curvature can prevent the flue gas from separating at the rear end.

[0165] In addition, a diamond-shaped tube with pointed ends at the left and right will cause excessive deformation at its left and right ends, making it prone to breakage. And due to structural limitations, the thickness at the two ends of the diamond-shaped tube is generally greater than that of other parts, resulting in an increased heat conduction path of the cooling water at the two ends of the diamond-shaped tube, which will reduce the heat exchange efficiency. However, setting it into a small arc structure can make the thickness at the two ends of the arc diamond-shaped tube close to that of other parts, and will not increase the heat conduction path of the cooling water at the two ends, and thus will not affect the heat exchange efficiency.

[0166] This embodiment achieves the purpose of increasing the heat exchange area at both ends of the cooling water pipe body 1020, and using the large arc end 1020b and the small arc end 1020a to reduce the resistance suffered by the cement kiln tail gas during flow, so that the cement kiln tail gas flows smoothly. Thus, the technical effect of increasing the contact area between the cement kiln tail gas and the cooling water pipe body 1020, making the cement kiln tail gas flow smoothly, and improving the cooling efficiency of the cement kiln tail gas is realized. Furthermore, the problem in the related technology that the cooling water pipe has a small heat exchange area and a large resistance to the flow of the cement kiln tail gas, and cannot well improve the cooling efficiency of the cement kiln tail gas is solved.

[0167] The connection line of the midpoints of the large arc ends 1020b at both ends of the short diagonal is perpendicular to the connection line of the small arc ends 1020a at both ends of the long diagonal.

[0168] Both the large arc end 1020b and the small arc end 1020a include inner rounded corners and outer rounded corners. To avoid the problem of thickness change of the cooling water pipe body 1020 at the upper and lower ends and the left and right ends due to the setting of the rounded corners, in this embodiment, the inner rounded corner and the outer rounded corner of the large arc end 1020b are concentrically arranged, and the inner rounded corner and the outer rounded corner of the small arc end 1020a are concentrically arranged.

[0169] Since the size design of the cross-section of the cooling water pipe body 1020 still has a great influence on the heat exchange efficiency, in order to rationally utilize space and improve the heat exchange efficiency, the applicable ranges of the sizes of the cross-section of the cooling water pipe body 1020 in this embodiment are as follows:

[0170] A = 20 - 100 mm;

[0171] B = A - 2A;

[0172] R 1 = 1 / 2 × A;

[0173] R 2 = R 1 - t;

[0174] r 1 = 6 ~ 1 / 2 × R 1 ;

[0175] r 2 = r 1 - t;

[0176] Wherein, A is the length of the short diagonal of the cooling water pipe body 1020; B is the length of the long diagonal of the cooling water pipe body 1020; R 1 is the outer diameter dimension of the large arc end 1020b; R 2 is the inner diameter dimension of the small arc end 1020a; t is the wall thickness of the cooling water pipe body 1020; r 1 is the outer diameter dimension of the small arc end 1020a; r 2 is the inner diameter dimension of the large arc end 1020b.

[0177] Since the cooling water pipe 102a in the present application is an arc-shaped rhombic pipe, compared with a circular pipe, it is more difficult to install, it is difficult to ensure the sealing performance of its connection, and it is not convenient to connect with the water inlet and return water pipelines. Therefore, the cooling water pipe 102a provided in this embodiment further includes an upper joint 22 and a lower joint 21 respectively arranged at both ends of the cooling water pipe body 1020; wherein, the upper joint 22 and the lower joint 21 have the same structure, and both include a plug 211 and a joint 213. The plug 211 is hermetically fixed at both ends of the cooling water pipe body 1020, and the first end of the joint 213 is hermetically fixed on the plug 211 and communicated with the inside of the cooling water pipe body 1020, and the second end extends out of the plug 211.

[0178] Specifically, it should be noted that the two ends of the cooling water pipe body 1020 are blocked by the plug 211. The cross-section of the plug 211 can be equal to or larger than the cross-section of the cooling water pipe body 1020, and the two ends of the cooling water pipe body 1020 are sealed through the plug 211. The installation position of the joint 213 can be provided through the plug 211, so that the joint 213 can be installed on the plug 211, and then the joint 213 is connected to the water inlet and return water pipelines. The joint 213 can be set to a structure convenient for connection, such as circular. Through the arrangement of the plug 211 and the joint 213, the technical effect of improving the sealing performance of the cooling water pipe body 1020 and at the same time facilitating the connection with the water inlet and return water pipelines is achieved, and further solves the problem that it is difficult to ensure the sealing performance of the connection during the installation of a non-circular cooling water pipe in the related art, and it is not convenient to connect with the water inlet and return water pipelines, resulting in a more troublesome installation.

[0179] Furthermore, the cross-section of the plug 211 is set to be the same arc-rhombus shape as that of the cooling water pipe body 1020. An adapter mounting hole is axially formed on the plug 211, and the adapter mounting hole communicates with the inside of the cooling water pipe; the first end of the adapter 213 is fixedly sealed in the adapter mounting hole.

[0180] To improve the sealing performance between the adapter 213 and the adapter mounting hole, the first end of the adapter 213 is threadedly connected to the adapter mounting hole, and thread sealant can be injected to enhance the sealing. To facilitate the connection between the adapter 213 and external equipment, the end of the adapter 213 away from the plug 211 is also provided with internal or external threads.

[0181] An annular groove is provided in the adapter mounting hole, and a sealing ring 212 is embedded in the annular groove. The adapter 213 is threadedly connected to the adapter mounting hole and presses the sealing ring 212 tightly in the annular groove, thereby improving the sealing performance between the adapter 213 and the adapter mounting hole.

[0182] In this application, as Figure 8 shown, the adjacent two rows of the cooling water pipe bodies 1020 and the three adjacent cooling water pipe bodies 1020 form a cooling water pipe unit arranged in a triangular pattern. The arrangement dimension range of the cooling water pipe unit is:

[0183] C = 1.8A to 2A;

[0184] D = 0.8B to 1.5B;

[0185] wherein, A is the maximum width dimension of the pipe cross-section; B is the maximum length dimension of the pipe cross-section; C is the center distance dimension between the pipe cross-sections of two adjacent cooling water pipe bodies 1020 in the same row; D is the center distance dimension between the pipe cross-sections of the cooling water pipe bodies 1020 in adjacent rows.

[0186] When the cooling water pipe 102a is an arc-rhombus pipe, A is the maximum width of the short diagonal of the arc-rhombus pipe; B is the maximum length of the long diagonal of the arc-rhombus pipe; C is the center distance between two adjacent arc-rhombus pipes in the same row; D is the horizontal center distance between two adjacent arc-rhombus pipes in adjacent rows.

[0187] Figure 13 shows a simplified diagram of the convective heat transfer of the low-temperature condensation module of this application. In the figure, s 1 is the row pitch of the staggered tube bundle, and s 2 is the column pitch of the staggered tube bundle.

[0188] For the heat transfer on the flue gas side of the low-temperature condensation module of this application, the fluid flows across the staggered tube bundle, and the relationship between the surface average heat transfer coefficient h and the dimensionless heat transfer coefficient Nu is:

[0189]

[0190] where l is the characteristic length and λ is the thermal conductivity of the fluid.

[0191] For the flue gas heat transfer condition under study, the Reynolds number range of its flow is approximately Re = 10 3 ~2×10 5 , and Nu can be expressed as:

[0192]

[0193] where s 1 is the row pitch of the staggered tube bundle, and s 2 is the column pitch of the staggered tube bundle. Re f is the Reynolds number of the flue gas flow, Pr f is the Prandtl number of the flue gas, and Pr w is the Prandtl number of the flue gas with the wall temperature as the characteristic temperature.

[0194] In engineering calculations, if the logarithmic mean temperature difference of convective heat transfer is given as Δt m , then according to the heat transfer equation, the overall heat transfer amount Φ is:

[0195] Φ = kAΔt m

[0196] where k is the comprehensive heat transfer coefficient and A is the heat transfer area.

[0197] As can be seen from the above analysis, the heat transfer area of the arc rhombus tube is larger than that of the circular tube. Therefore, using the arc rhombus tube as the cooling water pipe 102a in this application can increase the overall heat transfer amount of the equipment.

[0198] Using the arc rhombus tube will also affect the flow resistance of the flue gas. The circular tube and the preferred arc rhombus tube of this application will be compared and analyzed below.

[0199] The flow resistance relationship formula for the circular tube in staggered arrangement is:

[0200] When the gas flows around the tube bundle, the flow resistance is a function of the fluid velocity, the tube bundle arrangement, the fluid physical properties, and the number of rows. Its correlation formula is

[0201]

[0202] where χ is the correction coefficient of the staggered tube bundle, which is the relationship formula of the pipeline parameters s 1 , s 2 , N L is the number of pipeline rows, f is the resistance coefficient, and f is a value that depends on the change of the flow Reynolds number Re.

[0203] The flow resistance relationship formula for the arc rhombus tube in staggered arrangement is:

[0204] The long side of the arc rhombus tube is l 1, the short side is l 2 , with a design correction coefficient ε, the flow resistance relationship for the staggered arrangement of arc-rhombus tubes is as follows:

[0205]

[0206] where ε(l 1 , l 2 ) is the correction coefficient related to the side length of the arc-rhombus tube compared to the staggered tube bundle of circular tubes, and ε(l 1 , l 2 ) is greater than 1. The meanings of the other parameters are the same as those in the above formula.

[0207] The sides of the arc-rhombus are similar to the streamline properties of an airfoil. Compared with a circular tube, the flow boundary layer separation region at the tail is reduced, and the adverse pressure gradient is decreased, so the overall resistance will decrease.

[0208] As Figures 3A - 3B shown, the box body structure of the purification device in this application preferably adopts a rectangular box body structure. Specifically: The box body 101 includes an upper box plate 1011, a lower box plate 1012, a front box plate 1013, and a rear box plate 1014, and the upper box plate 1011, the front box plate 1013, the lower box plate 1012, and the rear box plate 1014 are hermetically connected in sequence; The left and right sides of the box body 101 are open to form a flue gas inlet 4 and a flue gas outlet 5 for flue gas circulation, and a flue gas purification channel from the flue gas inlet 4 to the flue gas outlet 5; The flue gas purification channel is used to accommodate a cooling water tube bundle 102 arranged vertically and in an array; A plurality of water pipe installation holes 102b for hermetically assembling the ends of the cooling water pipes 102a are provided on the upper box plate 1011 and the lower box plate 1012; Spaces for assembling end joint components for connecting the upper and lower ends of the cooling water tube bundle 102 are left above the upper box plate 1011 and below the lower box plate 1012. However, this application does not limit that the box body structure must be a rectangular structure. Those skilled in the art should understand that in some special application scenarios, the box body structure can be appropriately deformed, such as an arc-shaped box body structure with a certain curvature, such as a trapezoidal box body structure with different sizes of flue gas inlets and flue gas outlets, etc.

[0209] In this application, the upper and lower ends of the cooling water tube bundle 102 are installed on the upper box plate 1011 and the lower box plate 1012. Considering that the purification device needs to operate for a long time, when the low-temperature condensation module 1 works, the cooling water pipes 102a will be frequently vibrated by the impact of flue gas, which is likely to cause the problem of flue gas leakage at the connection between the upper and lower ends of the cooling water pipes 102a and the upper and lower box plates. To solve this problem, as Figures 9A to 10B shown, this application proposes a sealed installation structure for the cooling water pipe and the box plate. The sealed installation structure includes an installation base 20 and a cooling water pipe body 1020; where

[0210] A water pipe installation hole 102b is formed in the installation base 20, and an annular groove 17 is formed in the hole wall of the water pipe installation hole 102b along its circumferential direction; in this embodiment, the installation base 20 is the upper box plate 1011 and the lower box plate 1012 of the box body 101.

[0211] The end of the cooling water pipe body 1020 is arranged in the water pipe installation hole 102b, and an annular protrusion 18 is arranged on the part of the cooling water pipe body 1020 corresponding to the annular groove 17. The annular protrusion 18 is hermetically embedded in the annular groove 17 so that the end of the cooling water pipe body 1020 and the water pipe installation hole 102b form a curved surface seal.

[0212] In this embodiment, the cooling water pipe body 1020 has a long strip structure, and its interior is hollow and can be used for the flow of cooling water. The installation base 20 is the upper box plate 1011 or the lower box plate 1012 of the present application. In the prior art, in order to improve the sealing performance between the cooling water pipe body 1020 and the installation base 20, generally a sealing ring is fixed on the installation base 20, and the cooling water pipe body 1020 is fixed in the sealing ring, and the sealing performance at the connection between the cooling water pipe body 1020 and the installation base 20 is improved through the sealing ring.

[0213] However, since the outer side of the cooling water pipe body 1020 is still a straight curved surface structure, and the positions corresponding to the sealing ring and the installation base 20 are also straight curved surface structures, when the cooling water pipe body 1020 is installed on the sealing ring and the installation base 20, the straight curved surface structure is still difficult to maintain the sealing performance for a long time, resulting in an unsatisfactory sealing effect.

[0214] Therefore, to solve this problem, as Figure 9B and 10B shown, in this embodiment, a water pipe installation hole 102b is formed in the installation base 20, and an annular groove 17 is formed in the water pipe installation hole 102b. The end of the cooling water pipe body 1020 is sleeved in the water pipe installation hole 102b. To make the cooling water pipe body 1020 fit the annular groove 17, an annular protrusion 18 can be arranged on the outer side of the cooling water pipe body 1020, and the annular protrusion 18 is hermetically embedded in the annular groove 17, so that a curved surface seal is formed between the annular protrusion 18 and the annular groove 17.

[0215] Due to the provision of the annular groove 17, the inner surface of the water pipe installation hole 102b on the installation base 20 is transformed from a straight curved surface structure into a zigzag curved surface structure, and the outer surface of the end of the cooling water pipe body 1020 is transformed from a straight curved surface structure into a zigzag curved surface structure. It can be understood that when the cooling water pipe body 1020 is installed in the water pipe installation hole 102b, the connection part between the cooling water pipe body 1020 and the water pipe installation hole 102b is also transformed from a straight curved surface structure into a zigzag curved surface structure, thereby improving the sealing performance of the connection part between the cooling water pipe body 1020 and the water pipe installation hole 102b. And an interference fit can be adopted between the annular protrusion 18 and the annular groove 17 to further improve the sealing performance.

[0216] This embodiment achieves the technical effect of improving the sealing performance between the cooling water pipe body 1020 and the installation base 20 and preventing the tail gas from leaking from the connection part between the two, thereby solving the problem that in the related art, only sealant 16 or sealing rings are generally used for sealing between the cooling water pipe and the installation base 20, and the sealing performance is still difficult to meet the use requirements.

[0217] As Figure 9B and 10B shown, the annular groove 17 in the water pipe installation hole 102b can be formed by grooving with a special tooling. The width of the cross-section of the annular groove 17 can gradually decrease from the inside to the outside, so as to form a small arc end structure with a smaller diameter at its outermost end. Compared with a rectangular groove or other shaped groove structures, the structure of this annular groove 17 has better sealing performance when the annular protrusion 18 cooperates with it. And the annular protrusion 18 on the cooling water pipe body 1020 can be achieved by expanding the pipe. Specifically, the cooling water pipe body 1020 can be sleeved in the water pipe installation hole where the annular groove 17 has been opened, and through a special pipe expanding tooling, an outward expanding pressure is applied to the part of the cooling water pipe body 1020 corresponding to the annular groove 17, so that the cooling water pipe body 1020 deforms in the corresponding part, forming the first annular protrusion 18 and being pressed and fixed in the annular groove 17.

[0218] To further improve the sealing performance of the connection part between the cooling water pipe body 1020 and the installation base 20, sealant 16 is provided in the annular groove 17. The sealant 16 can be applied in the annular groove 17 before installing the cooling water pipe body 1020. When the cooling water pipe body 1020 is expanded to form the annular protrusion 18 and is embedded in the annular groove 17, the sealing performance is improved under the action of the sealant 16.

[0219] To improve the uniformity of the opening depth of the annular groove 17, the annular groove 17 is coaxially arranged with the water pipe installation hole.

[0220] As Figure 9B and 10BAs shown, a rubber gasket 15 is further provided in the annular groove 17, and the annular protrusion 18 presses the rubber gasket 15 tightly in the annular groove 17. The shape of the rubber gasket 15 matches that of the annular groove 17. The rubber gasket 15 can be first embedded in the annular groove 17, then the sealant 16 is injected into the annular groove 17, and finally the cooling water pipe body 1020 is sleeved in the water pipe installation hole 102b.

[0221] The annular groove 17 includes a plurality of grooves arranged at intervals circumferentially along the inner wall of the water pipe installation hole 102b, and the extending depths of the plurality of grooves on the inner wall are the same or different. The plurality of grooves can increase the contact points between the cooling water pipe body 1020 and the inner wall of the water pipe installation hole 102b. When the extending depths of the plurality of grooves are different, the sealing performance between different contact points can be different, and the depth of the grooves can be adjusted according to the actual exhaust gas flow situation to improve the scope of use.

[0222] To further improve the sealing performance at the connection between the cooling water pipe body 1020 and the installation base 20, the annular groove 17 is provided in a plurality and distributed axially along the water pipe installation hole 102b, so as to form a multi-stage seal, and the sealing method of each stage is the same.

[0223] To further improve the sealing performance, as Figure 10B shown, in this embodiment, the annular groove 17 is provided with two, including a first annular groove 171 and a second annular groove 172. The groove opening direction of the first annular groove 171 and the groove opening direction of the second annular groove 172 are inclined in opposite directions along the axial direction of the water pipe installation hole; correspondingly, the annular protrusion 18 includes a first annular protrusion 18 and a second annular protrusion 18, and the protrusion directions of the first annular protrusion 18 and the second annular protrusion 18 are inclined in opposite directions along the axial direction of the water pipe installation hole.

[0224] Specifically, it should be noted that the first annular groove 171 and the second annular groove 172 are arranged in sequence from inside to outside. The groove opening direction of the first annular groove 171 can be inclined towards the inside of the installation base 20, while the groove opening direction of the second annular groove 172 can be inclined towards the outside of the installation base 20, so that the connection between the cooling water pipe body 1020 and the water pipe installation hole 102b is sealed in different directions.

[0225] Moreover, in this embodiment, the depth of the second annular groove 172 is greater than the depth of the first annular groove 171. Through this setting method, the second annular groove 172 forms a secondary seal with better sealing performance, further improving the overall sealing performance at the connection.

[0226] After the annular groove 17 and the annular groove 17 located in the water pipe installation hole 102b cooperate, the sealing performance of the part in the water pipe installation hole 102b is effectively improved. However, the parts at both ends of the water pipe installation hole 102b are still straight curved surface structures, and their sealing performance still needs to be improved. Therefore, as Figure 10B shown, in this embodiment, two annular clamping protrusions 19 are further provided on the cooling water pipe body 1020. The two annular clamping protrusions 19 are located on the inner side and the outer side of the installation base 20, that is, at both ends of the water pipe installation hole 102b. The opposite surfaces of the two annular clamping protrusions 19 are respectively pressed against the inner side surface and the outer side surface of the installation base 20. The two annular clamping protrusions 19 are respectively used to form the first seal and the last seal at the connection between the cooling water pipe body 1020 and the installation base 20, which can further enhance the sealing performance and also improve the connection strength between the cooling water pipe body 1020 and the installation base 20.

[0227] As a preferred embodiment of the present application, the water pipe installation hole 102b is an arc-rhombus hole that is consistent with the cross-sectional contour and size of the end of the arc-rhombus pipe. The annular groove 17 includes a plurality of grooves, which are arranged in sequence on the four straight edges 1020c and the two large arc ends 1020b of the arc-rhombus hole. Correspondingly, the annular protrusion 18 includes a plurality of protrusions, which are arranged on the four straight edges 1020c and the two large arc ends 1020b of the end of the arc-rhombus pipe. The multiple grooves and the multiple protrusions are in an interference sealing fit, and combined with the interference depths of different grooves and protrusions, and then combined with the special shape of the arc-rhombus, the sealing performance at the connection between the cooling water pipe 102a and the installation base 20 (the upper box plate 1011 and the lower box plate 1012) can meet the requirements that the purification equipment can work for a long time without flue gas leakage.

[0228] In the present application, the structural form of the end joint assembly will affect the flow form of the cooling water from the cooling water inlet 103a to the cooling water return port 104a. The present application proposes five embodiments of the low-temperature condensation module 1 with different end joint assemblies.

[0229] Figures 2C - 2E An embodiment of the low-temperature condensation module with a round pipe elbow as the end joint is shown. It can be seen from the figure that the end joint assembly is a round pipe elbow assembly that sequentially connects the ends of two adjacent cooling water pipes 102a. Along the direction from the flue gas inlet 4 to the flue gas outlet 5, the ends of two adjacent rows of cooling water pipes 102 are connected by a round pipe elbow 105 located outside the box plate.

[0230] In this embodiment, the cooling water circulation pipeline is arranged above the box body 101 of the low-temperature condensation module 1. In other embodiments, it can also be arranged below, and the specific position is set according to actual needs. The cooling water circulation pipeline is set in two groups. The cooling water pipe bundle 102 is divided into two front and rear cooling water pipe areas 24 along the flue gas inlet 4 to the outlet direction in the box body 101. The cooling water inlet pipeline 103 and the cooling water return pipeline 104 of the two groups of cooling water circulation pipelines are respectively communicated with the inlet cooling water pipeline and the outlet cooling water pipeline of the front and rear two cooling water pipe areas 24. Since the flue gas temperature near the flue gas inlet 4 is high, a large cooling temperature drop is required for the cooling water pipe 102a near the flue gas inlet 4. On the basis of the cooling of the cooling water pipe 102a on the front side, the requirement for the cooling temperature drop of the cooling water pipe 102a near the flue gas outlet 5 is small. Therefore, in this embodiment, the cooling water flow rate in the cooling water pipe area 24 near the outlet side can be reduced, which can save the consumption of cooling water. Specifically, the way to reduce the cooling water flow rate in the cooling water pipe area 24 near the outlet side can be to reduce the pipe diameter (i.e., the cross-sectional area size) of the cooling water pipe 102a or to reduce the inlet flow rate of the cooling water inlet pipeline 103. In other embodiments, the cooling water flow rate in the cooling water pipe area 24 on the outlet side may not be reduced, that is, the cooling water consumption in the cooling water pipe area 24 on the inlet side is the same as the flow rate in the cooling water pipe area 24 on the outlet side. In addition, it should be noted that the present application does not limit the number of the cooling water pipe areas 24. In other embodiments, it can also be set to three, four, five, etc. according to actual needs.

[0231] In the above embodiment, since the number of the cooling water pipes 102 is large, the same number of round pipe elbows 105 are required. However, a large number of round pipe elbows 105 will cause kinetic energy resistance loss of the cooling water at the turning points, reducing the heat exchange efficiency of the low-temperature condensation module 1. At the same time, in order to reduce the overall volume of the low-temperature condensation module 1, the arrangement spacing of the cooling water pipes 102 is small. To connect the ends of two cooling water pipes 102 with the round pipe elbow 105, the radian of the round pipe elbow 105 is small, and the processing difficulty is large.

[0232] To solve the problems of large kinetic energy resistance loss of the cooling water at the round pipe elbow 105 and large processing difficulty of the round pipe elbow 105, as Figures 3A - 6D shown in the embodiment of using a water tank to replace the round pipe elbow 105 as the end joint assembly.

[0233] Specifically, the end joint assembly includes an upper end joint assembly 25 and a lower end joint assembly 26. The upper end joint assembly 25 and the lower end joint assembly 25 are alternately arranged in sequence above and below the cooling water pipe bundle 102 along the flue gas flow direction, and each end joint penetrates through the ends of multiple rows of cooling water pipes 102a to form a parallel pipeline in the cooling water pipe bundle 102 for at least two rows of parallel water flows to flow in the same direction. Specifically, the upper end joint assembly 25 is an upper water tank 11, and the lower end joint assembly 26 is a lower water tank 12. The upper water tank 11 includes a plurality of upper water tank sub-parts 111 arranged along the flue gas flow direction above the cooling water pipe bundle 102 as the end joints. The lower water tank 12 includes a plurality of lower water tank sub-parts 121 arranged along the flue gas flow direction below the cooling water pipe bundle 102 as the end joints. The multiple rows of cooling water pipes 102a penetrated by each water tank sub-part include an inlet water pipeline and an outlet water pipeline arranged side by side along the flue gas flow direction, and the number of rows of the inlet water pipeline and the outlet water pipeline is the same.

[0234] Figures 3A - 3D An embodiment showing the circulation of cooling water along the grouped water pipes is illustrated. In this embodiment, water tanks are arranged on the outer sides of the upper and lower tank plates of the box body 101 to replace the round pipe elbows 105 in Embodiment 1 to achieve the connection of the ends of the cooling water pipes 102. An upper water tank 11 is arranged above the upper tank plate 1011, and a lower water tank 12 is arranged below the lower tank plate 1012. A number of partition plates are arranged in the upper water tank 11 to divide the upper water tank 11 into the 1st to the Nth upper water tank sub-parts 111, and a number of partition plates are arranged in the lower water tank 12 to divide the lower water tank 12 into the 1st to the Nth lower water tank sub-parts 121. Each upper water tank sub-part 111 or lower water tank sub-part 121 correspondingly connects the ends of at least two rows of cooling water pipes 102. The cooling water inlet pipeline 103 connects to the 1st lower water tank sub-part 121 close to the flue gas inlet 4, and the cooling water return pipeline 104 connects to the Nth upper water tank sub-part 111 farthest from the flue gas inlet 4. The 2nd to the Nth lower water tank sub-parts 121 of the lower water tank 121 are respectively arranged in an interleaved manner with the 1st to the (N - 1)th upper water tank sub-parts 111 of the upper water tank 111. Specifically, as Figure 3AAs shown in the figure, the cooling water enters the first lower water tank section 121 of the lower water tank from the cooling water inlet. The first lower water tank section 121 corresponds to 4 rows of cooling water pipes 102a. Driven by the pressure of the water pump 9, the cooling water flows upward along these 4 rows of cooling water pipes 102a and flows out from the first 4 rows of cooling water pipes 102a in the first upper water tank section 111. It can be seen from the figure that the first upper water tank section 111 corresponds to and is connected to 8 rows of cooling water pipes 102a. The cooling water flowing in from the first 4 rows turns in the first upper water tank section 111 and then flows downward into the last 4 rows of cooling water pipes 102a. The second lower water tank section 121 corresponds to and is connected to 8 rows of cooling water pipes 102a. The cooling water in the 4 rows of cooling water pipes 102a flowing down from the first upper water tank section 111 turns in the second lower water tank section 121 and then flows upward out from the last 4 rows of cooling water pipes 102a. The second to N - 1 upper water tank sections 111 and the third to Nth lower water tank sections 121 are arranged in sequence according to the above rules. The cooling water circulates in the lower water tank section 121, the cooling water pipes 102a, and the upper water tank section 111 in sequence, and finally flows out from the cooling water return port on the Nth upper water tank section 11 of the upper water tank 11.

[0235] In this embodiment, the water tank section replaces the round pipe elbow in the above embodiment, making the cooling water route change from 1 - way turning in the above embodiment to multi - way turning, reducing the number of turns, also reducing the resistance loss of the cooling water turning, and improving the heat exchange efficiency of the cooling water pipe bundle; secondly, the water tank also reduces the processing difficulty and processing cost compared with the round pipe elbow.

[0236] For the flow resistance, since it flows inside the pipe, its flow resistance consists of the frictional resistance along the straight pipe section and the local resistances such as those flowing through elbows, joints, and sudden changes.

[0237] The frictional resistance is expressed as:

[0238] where λ is the frictional resistance coefficient, l is the pipe length, d is the inner diameter of the pipe, V i is the flow velocity inside the pipe, and g is the acceleration due to gravity;

[0239] The local resistance is expressed as:

[0240] where ξ is the local resistance coefficient and N is the number of local resistance components.

[0241] From the above two formulas, the longer the pipe length l, the greater h f is, the greater N is, the greater h ξ is. When changing from the elbow form to the integral water tank, the distance for the water flow from one side to the other side is greatly reduced, and the flow resistance consists only of a small section of frictional resistance and 2 local resistances. Because the tube bundle array changes from series arrangement to parallel arrangement, at this time, the flow resistance of each channel is the same and greatly reduced.

[0242] It should be noted that the water tank section in this application can also be independently arranged, that is, the water tank section is independently formed, and the water tank sections can be fixed to each other through a fixing structure. In addition, the shape of the water tank section is not limited to the rectangular shape in the embodiments of this application. In other embodiments, in order to further reduce the resistance loss of the cooling water turning, the outer right angle of the rectangular water tank section can also be processed into a rounded corner.

[0243] Considering that the flue gas temperature is high near the flue gas inlet 4 and the cooling water consumption is large, while the flue gas temperature is low far from the flue gas inlet 4 and the cooling water consumption is small. In order to further reduce the cooling water consumption, as the best embodiment of the low-temperature condensation module 1 of this application, Figures 4A - 4C An embodiment is shown in which the cooling water in each straight-through zone circulates along the grouped water pipes and the cooling water volume is adjustable. On the basis of the above embodiment in which the cooling water circulates along the grouped water pipes, the cooling water pipes 102 are divided into the 1st to the Nth zones, and a set of cooling water inlets 103a and cooling water outlets 104a are correspondingly arranged for each zone of the cooling water pipes 102. A plurality of cooling water pipe zones are isolated from each other and the cooling water circulates independently. This application achieves the purpose of saving the overall water consumption of the low-temperature condensation module 1 by reducing the water inflow of the cooling water pipe zone on the side far from the flue gas inlet 4. Specifically, in this embodiment, the cooling water pipes 102 are divided into three zones, and the cooling water consumption of the 1st to the 3rd zones is set to decrease in sequence. The number of zones for the cooling water pipes 102 in this application is not limited. In other embodiments, according to actual needs, the cooling water pipes 102 can be set to two zones, four zones, five zones, etc. Correspondingly, the cooling water inlets 103a and the cooling water outlets 104a are also set to two groups, four groups, five groups, etc.

[0244] Furthermore, in the embodiments of this application, the method of sequentially reducing the cooling water consumption on the side far from the flue gas inlet 4 is as follows: by setting a flow regulating valve 1031 at the cooling water inlet 103a of the first lower water tank section 121 in each cooling water pipe zone, the cooling water consumption of each cooling water pipe zone can be adjusted by adjusting the inlet area of the flow regulating valve 1031. Specifically, a water distribution pipe 1033 communicating with the lower water tank section 121 is arranged on the first lower water tank section 121 in each cooling water pipe zone, and a flow regulating valve 1031 is arranged on the water distribution pipe 1033.

[0245] Furthermore, a main cooling water inlet pipe 1032 is provided below the lower water tank 12 in each cooling water pipe area, which is respectively connected to each branch water pipe 1033. Cooling water enters from the main cooling water inlet pipe 1032. The main cooling water inlet pipe 1032 distributes the cooling water into each branch water pipe 1033 according to the opening sizes of the respective flow regulating valves 1031. In the embodiment of the present application, in order to save the overall water consumption of the cooling water, the openings of the flow regulating valves 1031 far from the flue gas inlet 4 are gradually reduced. In this way, the amount of cooling water flowing into the branch water pipes 1033 far from the flue gas inlet 4 is gradually reduced by the main cooling water inlet pipe, reducing the overall water consumption of the cooling water on the basis of meeting the condensation efficiency of the low-temperature condensation module 1.

[0246] As an alternative embodiment of the low-temperature condensation module 1 of the present application, the upper end joint assembly is an upper water tank that penetrates through the upper ends of all the cooling water pipes, and the lower end joint assembly is a lower water tank. The lower water tank includes a plurality of lower water tank subsections arranged along the flue gas flow direction, and each lower water tank subsection penetrates through multiple rows of the cooling water pipes; the upper water tank is connected to a cooling water return port, and each lower water tank subsection is connected to a cooling water inlet. It further includes a main cooling water inlet pipe, and the main cooling water inlet pipe is connected to each cooling water inlet through a flow regulating valve. Specifically, as Figures 5A - 5C shown in the direct-through type adjustable cooling water embodiment for each area, a plurality of partitions are provided in the lower water tank 12 to divide the lower water tank 12 into several lower water tank subsections 121. The number of cooling water pipes 102a corresponding to each group of lower water tank subsections 121 can be the same or different, which is specifically set according to actual needs. There are no partitions in the upper water tank 11, and the upper water tank is a return water tank that covers and connects the 1st to the Nth rows of cooling water pipes 102.

[0247] The cooling water enters from the main cooling water inlet pipe 1032 and is distributed to the corresponding lower water tank subsections 121 through the flow regulating valves 1031 of each branch water pipe 1033. In this embodiment, each lower water tank subsection 121 is an inlet water tank. The cooling water flows from each subsection upward along the cooling water pipe 102a into the upper water tank 11, and finally flows out from the cooling water return port 104a provided at the Nth row of cooling water pipes 102a.

[0248] Furthermore, considering that the flue gas temperature is high and the cooling water consumption is large near the flue gas inlet 4, and the flue gas temperature is low and the cooling water consumption is small far from the flue gas inlet 4, in order to further reduce the cooling water consumption of the low-temperature condensation module 1 in the embodiment of the present application, the cooling water amount of the subsections far from the flue gas inlet 4 side is set to be less than that of the subsections near the flue gas inlet 4 side. Specifically, along the direction from the flue gas inlet 4 to the outlet, the openings of the flow regulating valves 1031 of the branch water pipes 1033 of each subsection are gradually reduced.

[0249] As a replaceable embodiment of the low-temperature condensation module 1 of the present application, the upper end joint assembly 25 is the upper water tank 11 that penetrates through the upper ends of all the cooling water pipes 102a, and the lower end joint assembly 26 is the lower water tank 12 that penetrates through the lower ends of all the cooling water pipes 102a. One of the upper water tank 11 and the lower water tank 12 is connected to the cooling water inlet 103a, and the other is connected to the cooling water return port 104a. Specifically, as shown in Figures 6A - 6D the embodiment where the cooling water in each straight-through zone circulates along the grouped water pipes and the cooling water volume is adjustable. There is no partition in the upper water tank 11, and the upper water tank 11 is a return water tank connected to the cooling water return port 104a; there is no partition in the lower water tank 12, and the lower water tank 12 is a water inlet tank connected to the cooling water inlet 103a. Both the upper water tank 11 and the lower water tank 12 cover and are connected to the 1st to Nth rows of cooling water pipes 102a. The cooling water enters the lower water tank 12 from the cooling water inlet 103a, then flows upward from each row of cooling water to the upper water tank 11, and finally flows out from the cooling water return port 104a provided at the Nth row of cooling water pipes 102a.

[0250] Furthermore, considering that the flue gas temperature is high and the cooling water consumption is large near the flue gas inlet 4, and the flue gas temperature is low and the cooling water consumption is small far from the flue gas inlet 4. In order to further reduce the cooling water consumption of the low-temperature condensation module 1, in the embodiment of the present application, along the direction from the flue gas inlet 4 to the outlet, the opening sizes of the connections between the lower water tank 12 and each row of cooling water pipes 102a are sequentially reduced, so that the cooling water volumes of each row of cooling water pipes 102a from the flue gas inlet 4 to the outlet direction are sequentially reduced, thereby realizing the overall water consumption of the low-temperature condensation module 1.

[0251] In addition, as shown in Figure 3C 、 4C 、5C, and 6C, the cooling water inlet 103a and the cooling water return port 104a are both arranged on opposite sides, so that the running distances and resistances of the cooling water in each parallel-flowing sub-water pipe 1033 are the same, to ensure that the water flow rates in each parallel sub-water pipe 1033 are the same and their cooling efficiencies for the corresponding flue gas are the same.

[0252] In addition, in order to ensure the overall aesthetic appearance of the purification equipment in the present application, a closed grille cover is installed on the outside of the lower box plate 1012 to cover the water tank or elbow 105 exposed at the bottom of the box body 101.

[0253] The embodiment of the present application also provides a low-temperature condensation module 1 with a demisting, water collection, and water blocking plate structure.

[0254] The flue gas velocity of the flue gas discharged from the cement kiln is high, and the heat exchange and condensation time through the low-temperature condensation module 1 is short. If the ammonia-containing condensate in the flue gas does not completely flow along the cooling water pipe 102a to the bottom of the device for external discharge, the ammonia-containing condensate will be discharged to the outside from the flue gas outlet 5, causing pollution. Therefore, in this embodiment, a demisting, water-collecting and water-blocking plate 13 is arranged at the flue gas outlet to further collect the moisture in the flue gas cooled to the dew point.

[0255] In order to further ensure that the ammonia-containing condensate will not be discharged to the outside from the flue gas outlet 5, in the embodiment of the present application, as Figure 3A shown, a plurality of vertically arranged demisting, water-collecting and water-blocking plates 13 are arranged at the flue gas outlet 5. The plate surface of the demisting, water-collecting and water-blocking plate 13 is a folding plate with a plurality of folding angles. After the flue gas is discharged from the last row of cooling water pipes 102a, it will pass through the demisting, water-collecting and water-blocking plate 13. Under the action of the folding surface of the folding plate, the velocity of the flue gas will decrease, and the condensate in the flue gas will adhere to the surface of the demisting, water-collecting and water-blocking plate 13 and flow down along the surface of the demisting, water-collecting and water-blocking plate 13 to the bottom of the device. By arranging the demisting, water-collecting and water-blocking plate 13, the condensate in the flue gas can be blocked from being discharged to the outside from the flue gas port.

[0256] Furthermore, the folding plate at least includes a pair of folding angles bent in opposite directions. In this way, the travel distance of the flue gas on the folding plate can be increased, which is beneficial to the collection of the moisture mixed in the flue gas.

[0257] As a preferred embodiment, a straight plate section is arranged at a section of the folding plate close to the flue gas outlet, and its function is to guide the flue gas to flow along the demisting, water-collecting and water-blocking plate 13. Furthermore, at least part of the demisting, water-collecting and water-blocking plate 13 is formed with oblong holes extending vertically along the surface of the demisting, water-collecting and water-blocking plate 13 as drainage holes, and the condensate adhering to the surface of the demisting, water-collecting and water-blocking plate 13 will flow down along the oblong holes to the bottom of the device for external discharge. Preferably, the oblong holes extend from the upper end to the lower end of the folding plate.

[0258] In order to further improve the safety of flue gas discharge, a wire mesh 14 is arranged outside the demisting, water-collecting and water-blocking plate 13 to make a final barrier to the condensate in the flue gas.

[0259] In summary, the self-sustaining one-step purification equipment provided by the present application is applied to flue gas purification treatment scenarios such as cement kilns, power plants or coal yards, and can effectively reduce the contents of escaped ammonia, SO 2 , NOx, CO 2 and the dust content in the discharged flue gas.

[0260] In an embodiment of the purification equipment of the present application, when the flue gas temperature at the flue gas inlet is 105 °C, the moisture content of the flue gas is 9.5%, the escaped ammonia is 20 mg / m 3 , SO 2 content is 15 mg / m 3, NOx content 38 mg / m 3 , CO 2 concentration 20.5%, dust content 6 mg / m 3 , when the water temperature at the inlet of the cooling water is 28 °C,

[0261] (1) The air temperature at the flue gas outlet is 60 °C, the moisture content of the flue gas is 6.5%, and the escaped ammonia is 6 mg / m 3 , SO 2 content 5 mg / m 3 , NOx content 34 mg / m 3 , CO 2 concentration 18.5%, dust content 3 mg / m 3 , and the water temperature at the outlet of the cooling water is 46 °C.

[0262] (2) When increasing the cooling water volume in the low-temperature condensation module to make the air temperature at the flue gas outlet of the purification equipment 50 °C, the moisture content of the flue gas is 5.0%, and the escaped ammonia is 3 mg / m 3 , SO 2 content 2 mg / m 3 , NOx content 32 mg / m 3 , CO 2 concentration content 17.5%, dust content 2 mg / m 3 , and the water temperature at the outlet of the cooling water is 41 °C.

[0263] In another embodiment of the purification equipment of the present application, when the flue gas air temperature at the flue gas inlet is 150 °C, the moisture content of the flue gas is 7.5%, and the escaped ammonia is 80 mg / m 3 , SO 2 content 150 mg / m 3 , NOx content 40 mg / m 3 , CO 2 concentration 21.0%, dust content 5 mg / m 3 , when the water temperature at the inlet of the cooling water is 28 °C,

[0264] the air temperature at the flue gas outlet is 65 °C, the moisture content of the flue gas is 6.0%, and the escaped ammonia is 15 mg / m 3 , SO 2 content 42 mg / m 3 , NOx content 36 mg / m 3 , CO 2 concentration 19.0%, dust content 3 mg / m 3 , and at this time the water temperature at the outlet of the cooling water is 65 °C.

[0265] For the case where the flue gas air temperature at the flue gas inlet is relatively high, or the moisture content of the flue gas is relatively low, or the escaped ammonia content at the flue gas inlet is relatively high, in order to further improve the purification efficiency of the escaped ammonia, such as Figure 1B andFigure 2A As shown in the figure, an embodiment of the present application provides a self-sustaining one-step purification device with an atomization device. The atomization device 3 is used to spray atomized water towards the flue gas inlet 4. The installation position of the atomization device 3 is at the flue gas inlet 4. More specifically, the atomization device 4 is arranged at the trapezoidal joint of the connection position between the flue gas discharge port of the cement kiln and the flue gas inlet 4 of the purification device. However, it should be noted that the installation position of the atomization device 3 is not limited to the flue gas inlet 4. For example, in some other embodiments, the atomization device 3 can also be arranged at the flue gas discharge port of the cement kiln or a more forward position. Spraying atomized water towards the flue gas inlet can increase the water content in the flue gas. The specific principle is as follows: Since the temperature of the flue gas is high, the atomized water will be evaporated into water vapor by the high temperature of the flue gas after entering the flue gas, thus increasing the water vapor content in the flue gas. When the water vapor content in the flue gas is low, spraying atomized water through the atomization device 3 can increase the water vapor content in the flue gas, thereby improving the ammonia removal efficiency. In addition, a medicament (a medicament helpful for ammonia removal, denitration, and desulfurization) can also be added to the atomized water. By adding the medicament in the form of atomized water, the medicament can be fully contacted with the flue gas, further improving the cleanliness of the discharged flue gas. Finally, the atomized water can also cool the flue gas, reducing the working pressure of the subsequent low-temperature condensation module 1.

[0266] The atomization device includes an atomization water tank, a spraying system, and a spraying water pipe connected in sequence. The atomization water tank is connected to a water source, and the spraying water pipe is arranged at the flue gas inlet for spraying atomized water towards the flue gas inlet.

[0267] Furthermore, the atomization device further includes an atomized water flow control mechanism for controlling the water volume of the spraying water pipe spraying atomized water towards the flue gas inlet.

[0268] When the flue gas temperature at the flue gas inlet is greater than 120 °C, or the moisture content of the flue gas at the flue gas inlet is less than 8%, or the escaped ammonia at the flue gas inlet is 100 mg / m 3 , the atomization device is started.

[0269] When the SO 2 content at the flue gas inlet is greater than 100 mg / m 3 , the atomization device is started, and a desulfurization medicament is added to the atomized water; and / or when the Nox content at the flue gas inlet is greater than 50 mg / m 3 , the atomization device is started, and a denitration medicament is added to the atomized water.

[0270] In an embodiment of the purification device of the present application, when the flue gas temperature at the flue gas inlet is 150 °C, the moisture content of the flue gas is 7.5%, the escaped ammonia is 80 mg / m 3 , and the SO 2 content is 150 mg / m 3, NOx content 40 mg / m 3 , CO 2 Concentration 21.0%, dust content 5 mg / m 3 , when the inlet water temperature of the cooling water is 28 °C,

[0271] Activate the atomization device 3, adjust the moisture content of the inlet flue gas to 9.0%, reduce the inlet air temperature to 128 °C, and increase the cooling water volume so that when the flue gas outlet temperature of the purification equipment is 55 °C, the moisture content of the flue gas is 5.0% and the escaped ammonia is 4 mg / m 3 , SO 2 18 mg / m 3 , NOx content 34 mg / m 3 , CO 2 Concentration 17.8%, dust content 1.5 mg / m 3 , at this time the outlet water temperature of the cooling water is 48 °C.

[0272] As a preferred embodiment of the present application, the purification equipment further includes a spray cleaning device 2. Since the flue gas contains particulate matter, the particulate matter will adhere to the surface of the cooling water pipe 102 of the low-temperature condensation module 1 during long-term contact with the flue gas and is difficult to remove, reducing the heat exchange efficiency of the low-temperature condensation module 1 (i.e., the cooling efficiency of the flue gas). Therefore, as Figure 1B shown, water is sprayed through the spray device 2 at the connection between the flue gas outlet 5 of the cement kiln and the ammonia removal device. The sprayed water is sprayed in a columnar shape to the flue gas port and is washed onto the surface of the cooling water pipe fittings by the fast-flowing flue gas blown out from the flue gas outlet 5 of the cement kiln, washing away the particulate matter adhered to the surface of the pipe fittings.

[0273] The embodiment of the present application also provides a purification process using the above self-sustained one-step purification equipment for purifying the flue gas of the flue gas emission equipment to be purified. The purification process mainly includes the following steps:

[0274] Install the self-sustained one-step high-efficiency purification equipment at the flue gas outlet of the flue gas emission equipment to be purified, and seal the flue gas inlet of the self-sustained one-step high-efficiency purification equipment with the flue gas outlet of the flue gas emission equipment to be purified;

[0275] Start the self-sustained one-step high-efficiency purification equipment to work. By cooling the flue gas, the water vapor in the flue gas is condensed into condensed water, and the ammonia gas and acidic pollutants contained in the flue gas dissolve in the condensed water and undergo an acid-base neutralization reaction to form non-volatile salts that are easily soluble in the condensed water.

[0276] In order to improve the ammonia removal rate, further, the purification process further includes: by arranging an atomizing device at the flue gas inlet, spraying atomized water at the flue gas inlet to increase the water vapor content in the flue gas. Experiments have shown that the ammonia removal rate can be greatly improved by increasing the water vapor content in the flue gas.

[0277] Since the flue gas contains particulate matter, the cooling water pipe 102 of the low-temperature condensation module 1 is in long-term contact with the flue gas, resulting in particulate matter adhering to the surface of the cooling water pipe fittings and being difficult to remove, reducing the heat exchange efficiency of the low-temperature condensation module 1 (i.e., the cooling efficiency of the flue gas). Therefore, the purification process further includes: spraying water through the spraying device 2 at the connection between the outlet 5 of the cement kiln flue gas and the inlet of the flue gas of the self-sustaining one-step purification device. The sprayed water is in a columnar shape and sprays onto the flue gas port, and is washed onto the surface of the pipe fittings by the rapidly flowing flue gas blown out from the outlet 5 of the cement kiln flue gas, washing away the particulate matter adhering to the surface of the pipe fittings.

[0278] In addition, the purification process further includes: treating the salt-containing condensate water collected at the bottom of the self-sustaining one-step high-efficiency purification device into purified water that can be recycled or discharged and high-concentration salt-containing water by membrane separation, and spraying the high-concentration salt-containing water onto the grate cooler of the flue gas emission device to be purified. The advantages of this step have been described above and will not be elaborated here.

[0279] The embodiment of the present application also provides a modular purification device, modularizing the purification device in the above embodiment. The modular purification device includes several purification device sub-modules, and several purification device sub-modules can be arranged in parallel and / or in series. Standardize the sub-modules, and determine the number of sub-modules and the connection method between sub-modules according to requirements and on-site layout.

[0280] Specifically, in an embodiment of the present application, one purification device can be made into two purification device sub-modules. During on-site installation, the two purification device sub-modules are placed side by side. Further, in order to ensure the connection reliability between the two sub-modules, the two purification device sub-modules can be connected by bolts and welding.

[0281] In addition, the sub-modules can also be placed at intervals. The outlet 5 of the cement kiln flue gas is split into each branch pipe and enters each sub-module respectively, and finally the flue gas of all sub-modules is collectively discharged.

[0282] Since the sub-modules are of standardized design, when the actual application scenario exceeds the purification capacity of the sub-modules, several sub-modules can be connected in series along the flue gas flow direction for use.

[0283] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A self-sustaining one-step purification device, characterized in that, it is used for purifying flue gas containing water vapor, ammonia and acidic pollutants; the purification device includes: a flue gas inlet and a flue gas outlet, and a flue gas purification channel from the flue gas inlet to the flue gas outlet; a low-temperature condensation module, which is arranged in the flue gas purification channel, cools and condenses the flue gas entering the flue gas purification channel from the flue gas inlet, condenses the water vapor into condensed water, and the ammonia and the acidic pollutants dissolve in the condensed water and undergo an acid-base neutralization reaction in the condensed water to form a non-volatile salt that is easily soluble in the condensed water; the low-temperature condensation module is connected to a cooling water inlet and a cooling water return port; the low-temperature condensation module includes a cooling water pipe bundle vertically arranged and arranged in an array in the flue gas purification channel and end joint assemblies connected to the upper and lower ends of the cooling water pipe bundle, and the end joint assemblies together with the cooling water pipe bundle form a cooling water circulation pipeline for the cooling water to flow from the cooling water inlet to the cooling water return port; the cooling water pipe bundle is arranged in a staggered row pipe bundle array; the cooling water pipe bundle is divided into several cooling water pipe areas along the flue gas flow direction, and each cooling water pipe area includes multiple rows of cooling water pipes arranged along the flue gas flow direction, and the adjacent two rows of cooling water pipes in the multiple rows of cooling water pipes are staggered in the flue gas flow direction and there is no gap between the orthographic projection surfaces; the cooling water pipe is an arc rhombus cooling water pipe, and the arc rhombus cooling water pipe further includes an upper joint and a lower joint respectively arranged at the vertical two ends of the cooling water pipe body; wherein, the upper joint and the lower joint have the same structure and both include a plug and a joint.

2. The self-sustaining one-step purification device according to claim 1, characterized in that, the arrangement dimension range of the cooling water pipe unit is: C = 1.8A to 2A; D = 0.8B to 1.5B; wherein, A is the maximum width dimension of the pipe cross-section; B is the maximum length dimension of the pipe cross-section; C is the center distance dimension of the pipe cross-sections of two adjacent cooling water pipes in the same row; D is the center distance dimension of the pipe cross-sections of adjacent rows of cooling water pipes.

3. The self-sustaining one-step purification device according to claim 1, characterized in that, the arc rhombus cooling water pipe includes: a cooling water pipe body, the cross-section of the cooling water pipe body is in the shape of an arc rhombus, the two ends of its short diagonal are large arc ends respectively, and the two ends of the long diagonal are small arc ends respectively; the large arc ends at the two ends of the short diagonal and the small arc ends at the two ends of the long diagonal are respectively connected by straight edges, and the straight edges are tangent to the arc lines of the large arc ends and the small arc ends.

4. The self-sustaining one-step purification device according to claim 3, characterized in that, the large arc ends at the two ends of the short diagonal are concentrically arranged.

5. The self-sustaining one-step purification device according to claim 3, characterized in that, the connection line of the midpoints of the large arc ends at the two ends of the short diagonal is perpendicular to the connection line of the small arc ends at the two ends of the long diagonal.

6. The self-sustaining one-step purification device according to claim 3, characterized in that, Both the large arc end and the small arc end include an inner fillet and an outer fillet.

7. The self-sustaining one-step purification device according to claim 4, characterized in that the applicable ranges of the dimensions of the cross-section of the cooling water pipe body are as follows: A = 20 to 100 mm; B = A to 2A; R 1 = 1 / 2 × A; R 2 = R 1 - t; r 1 ＝6～1 / 2×R 1 ； r 2 ＝r 1 -t； Among them, A is the length of the short diagonal of the cooling water pipe body; B is the length of the long diagonal of the cooling water pipe body; R 1 is the outer diameter dimension of the large arc end; R 2 is the inner diameter dimension of the large arc end; t is the wall thickness of the cooling water pipe body; r 1 is the outer diameter dimension of the small arc end; r 2 is the inner diameter dimension of the small arc end.

8. The self-sustaining one-step purification device according to claim 3, characterized in that the plug is hermetically fixed at the vertical two ends of the cooling water pipe body, the first end of the joint is hermetically fixed on the plug and communicated with the inside of the cooling water pipe body, and the second end extends out of the plug.

9. The self-sustaining one-step purification device according to claim 8, characterized in that the cross-section of the plug is set to an arc-rhombus shape the same as that of the cooling water pipe body, and a joint installation hole is axially formed on the plug; the first end of the joint is hermetically fixed in the joint installation hole.

10. The self-sustaining one-step purification device according to claim 9, characterized in that an annular groove is provided in the joint installation hole, a sealing ring is embedded in the annular groove, and the joint is threadedly connected with the joint installation hole and presses the sealing ring in the annular groove.

11. The self-sustaining one-step purification device according to claim 1, characterized in that the end joint assembly includes an upper end joint assembly and a lower end joint assembly, the upper end joint assembly and the lower end joint assembly are alternately arranged in sequence above and below the cooling water pipe bundle along the flue gas flow direction, and each end joint penetrates through the ends of multiple rows of cooling water pipes to form a parallel pipeline in the cooling water pipe bundle for at least two rows of parallel water flows to flow in the same direction.

12. The self-sustaining one-step purification device according to claim 11, characterized in that the upper end joint assembly is an upper water tank, the lower end joint assembly is a lower water tank, the upper water tank includes a plurality of upper water tank sub-parts arranged along the flue gas flow direction above the cooling water pipe bundle as the end joints, the lower water tank includes a plurality of lower water tank sub-parts arranged along the flue gas flow direction below the cooling water pipe bundle as the end joints, the multiple rows of cooling water pipes penetrated by each water tank sub-part include a water inlet pipeline and a water outlet pipeline arranged side by side along the flue gas flow direction, and the number of rows of the water inlet pipeline and the water outlet pipeline is the same.

13. The self-sustaining one-step purification device according to claim 12, characterized in that one of the upper water tank and the lower water tank further includes a cooling water inlet tank communicated with the cooling water inlet, and the other further includes a cooling water return tank communicated with the cooling water return port, and both the cooling water inlet tank and the cooling water return tank correspondingly penetrate through at least two rows of cooling water pipes.

14. The self-sustaining one-step purification device according to claim 13, characterized in that The cooling water pipe bundle is divided into multiple cooling water pipe areas along the flue gas flow direction. Each cooling water pipe area includes multiple rows of cooling water pipes arranged along the flue gas flow direction, and each cooling water pipe area is correspondingly connected to a set of the cooling water inlet and the cooling water return outlet. The cooling water flows between multiple cooling water pipe areas are not connected within the cooling water pipe bundle.

15. The self-sustaining one-step purification device according to claim 14, wherein, the cooling water flow rate in the cooling water pipe area near the flue gas outlet is less than the cooling water flow rate in the cooling water pipe area near the flue gas inlet.

16. The self-sustaining one-step purification device according to claim 15, wherein, the cooling water pipe area is set to three, and the cooling water flow rate in the cooling water pipe area decreases in sequence along the flue gas flow direction.

17. The self-sustaining one-step purification device according to claim 15, wherein, it further includes a cooling water inlet main pipe, and the cooling water inlet main pipe is connected to each cooling water inlet through a flow regulating valve.

18. The self-sustaining one-step purification device according to claim 11, wherein, the upper end joint assembly is an upper water tank that penetrates through the upper ends of all cooling water pipes, and the lower end joint assembly is a lower water tank that penetrates through the lower ends of all cooling water pipes. One of the upper water tank and the lower water tank is connected to the cooling water inlet, and the other is connected to the cooling water return outlet.

19. The self-sustaining one-step purification device according to claim 18, wherein, the cooling water flow rate in the cooling water pipe area from the flue gas inlet to the flue gas outlet decreases in sequence.

20. The self-sustaining one-step purification device according to claim 11, wherein, the upper end joint assembly is an upper water tank that penetrates through the upper ends of all cooling water pipes, and the lower end joint assembly is a lower water tank. The lower water tank includes multiple lower water tank sections arranged along the flue gas flow direction, and each lower water tank section penetrates through multiple rows of the cooling water pipes; the upper water tank is connected to a cooling water return outlet, and each lower water tank section is connected to a cooling water inlet.

21. The self-sustaining one-step purification device according to claim 20, wherein, it further includes a cooling water inlet main pipe, and the cooling water inlet main pipe is connected to each cooling water inlet through a flow regulating valve.

22. The self-sustaining one-step purification device according to claim 1, wherein, the end joint assembly is a circular pipe elbow assembly that sequentially connects the ends of adjacent two of the cooling water pipes.

23. The self-sustaining one-step purification device according to claim 22, wherein, each cooling water pipe area is connected to a water collecting pipe and a return pipe.

24. The self-sustaining one-step purification device according to claim 3, wherein, It further includes a box body, and the two sides of the box body are provided with the flue gas inlet and the flue gas outlet; water pipe installation holes for installing the upper end part and the lower end part of the cooling water pipe bundle are formed on the upper box plate and the lower box plate of the box body, and an annular groove is formed along the circumferential direction of the hole wall of the water pipe installation hole; the end part of the cooling water pipe is arranged in the water pipe installation hole, and a part of the cooling water pipe body corresponding to the annular groove is provided with an annular protrusion, and the annular protrusion is hermetically embedded in the annular groove so that the end part of the cooling water pipe body and the water pipe installation hole form a curved surface seal.

25. The self-sustaining one-step purification device according to claim 24, characterized in that sealant is arranged in the annular groove.

26. The self-sustaining one-step purification device according to claim 25, characterized in that the annular groove is coaxially arranged with the water pipe installation hole.

27. The self-sustaining one-step purification device according to claim 25, characterized in that a rubber gasket is further arranged in the annular groove, and the annular protrusion presses the rubber gasket tightly in the annular groove.

28. The self-sustaining one-step purification device according to claim 24, characterized in that the annular groove includes a plurality of grooves arranged at intervals along the circumferential direction of the hole wall of the water pipe installation hole, and the extending depths of the plurality of grooves on the hole wall are the same or different.

29. The self-sustaining one-step purification device according to claim 28, characterized in that the annular groove is provided in a plurality and is distributed along the axial direction of the water pipe installation hole.

30. The self-sustaining one-step purification device according to claim 29, characterized in that the annular groove is provided in two, including a first annular groove and a second annular groove, and the groove opening direction of the first annular groove and the groove opening direction of the second annular groove are inclined in opposite directions along the axial direction of the water pipe installation hole; correspondingly, the annular protrusion includes a first annular protrusion and a second annular protrusion, and the protrusion directions of the first annular protrusion and the second annular protrusion are inclined in opposite directions along the axial direction of the water pipe installation hole.

31. The self-sustaining one-step purification device according to claim 28, characterized in that two annular clamping protrusions are further arranged on the cooling water pipe body, the two annular clamping protrusions are located on the inner side and the outer side of the installation base, and the opposite surfaces of the two annular clamping protrusions are respectively pressed against the inner side surface and the outer side surface of the installation base.

32. The self-sustaining one-step purification device according to claim 1, characterized in that it further includes a plurality of demisting, water collecting and water blocking plates vertically arranged at the flue gas outlet, and the plate surface of the demisting, water collecting and water blocking plates is a corrugated surface.

33. The self-sustaining one-step purification device according to claim 32, characterized in that at least part of the demisting, water collecting and water blocking plates are formed with long round holes extending vertically along the surface of the demisting, water collecting and water blocking plates.

34. The self-sustaining one-step purification device according to claim 32, characterized in that it further includes a wire mesh arranged outside the demisting, water collecting and water blocking plates.

35. The self-sustaining one-step purification equipment according to any one of claims 1-34, characterized in that, it further includes an atomizing device, which is arranged at the flue gas inlet, and atomized water is sprayed towards this place to increase the water content in the flue gas.

36. The self-sustaining one-step purification equipment according to claim 35, characterized in that, pharmaceuticals for ammonia removal and / or desulfurization and / or denitration are added to the atomized water of the atomizing device.

37. The self-sustaining one-step purification equipment according to any one of claims 1-34, characterized in that, it further includes a spray cleaning device, which is arranged at the flue gas inlet and is used to spray cleaning water into the flue gas. The cleaning water flushes the surface of the cooling water pipe of the low-temperature condensation module along with the flue gas to wash away the particulate matter adhered to the pipe surface.

38. The self-sustaining one-step purification equipment according to claim 1, characterized in that, the box body includes an upper box plate, a lower box plate, a front box plate and a rear box plate. The upper box plate is hermetically connected to the front box plate and the rear box plate, and the lower box plate is hermetically connected to the front box plate and the rear box plate, jointly forming the upper, lower, front and rear seals of the low-temperature condensation module. The left and right directions of the purification equipment are the flue gas inlet and the flue gas outlet.

39. The self-sustaining one-step purification equipment according to claim 1, characterized in that, it further includes a condensate collection device arranged at the bottom of the low-temperature condensation module for collecting the condensate, and the condensate collection device is connected to a condensate discharge port.

40. The self-sustaining one-step purification equipment according to claim 1, characterized in that, the acidic pollutants include at least one of sulfur dioxide, carbon dioxide, and NOx.

41. A purification process using the self-sustaining one-step purification equipment according to any one of claims 1-40, characterized in that, it includes the following steps: Install the self-sustaining one-step purification equipment at the flue gas outlet of the flue gas emission equipment to be purified, and hermetically connect the flue gas inlet of the self-sustaining one-step purification equipment to the flue gas outlet of the flue gas emission equipment to be purified; Start the self-sustaining one-step purification equipment to work. By cooling the flue gas, the water vapor in the flue gas is condensed into condensate, and the ammonia and acidic pollutants contained in the flue gas itself dissolve in the condensate to undergo an acid-base neutralization reaction to generate non-volatile salts that are easily soluble in the condensate.

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