Flue gas purification and waste heat recovery system and waste heat recovery device

Abstract

The utility model discloses a flue gas purification and waste heat utilization system and a waste heat recovery device. The flue gas purification and waste heat utilization system comprises a first waste heat boiler unit, a flue gas filtering dust remover unit, an SCR denitration reactor unit and a second waste heat boiler unit, wherein water vapor generated by at least the first waste heat boiler unit in the first waste heat boiler unit and the second waste heat boiler unit becomes condensate water after acting through a steam generator, and the condensate water returns to the first waste heat boiler unit and / or the second waste heat boiler unit after being deoxygenized through a deaerator; and the condensate water heater is used for obtaining the second cooled flue gas and heating the condensate water into heated condensate water by using the second cooled flue gas, and the heated condensate water returns to the first waste heat boiler unit and / or the second waste heat boiler unit after being deoxygenized by a deaerator. The temperature of the heated condensate water entering the deaerator is increased, and independent heat supply to the deaerator can be reduced or even eliminated.

Description

Technical Field

[0001] This utility model relates to the field of industrial kiln flue gas treatment technology, specifically to a flue gas purification and waste heat recovery system and a waste heat recovery device. Background Technology

[0002] The applicant disclosed an industrial silicon smelting flue gas treatment system in patent document CN114887409A. The system first adjusts the industrial silicon smelting flue gas, which is emitted from the industrial silicon smelting furnace at a temperature of 450℃-650℃, to a first cooled flue gas at a temperature of 300℃-450℃ through a first waste heat boiler unit. Then, the first cooled flue gas is filtered and purified by a flue gas filter dust collector unit to become dust-removed flue gas. Next, the dust-removed flue gas is denitrified by an SCR denitrification reactor unit to obtain denitrified flue gas. After that, the denitrified flue gas is adjusted to a second cooled flue gas at a temperature of 100℃-200℃ through a second waste heat boiler unit. Finally, the second cooled flue gas enters a desulfurization device for desulfurization.

[0003] Furthermore, the patent document further discloses: (I) an integrated heat exchange device and an integrated dust removal and denitrification device in an industrial silicon smelting flue gas treatment system. Specifically, the shell of the flue constituting the first waste heat boiler unit and the shell of the flue constituting the second waste heat boiler unit are assembled together to make the first waste heat boiler unit and the second waste heat boiler unit an integrated heat exchange device; the SCR denitrification reactor unit is assembled on the flue gas filter dust collector unit to form an integrated dust removal and denitrification device; the integrated heat exchange device is surrounded by an air supply flue and a return flue, the flue gas filter dust collector unit and the SCR denitrification reactor unit are arranged beside the integrated heat exchange device, the integrated heat exchange device connects the exhaust port of the flue of the first waste heat boiler unit to the air inlet of the flue gas filter dust collector unit through the air supply flue, and the integrated heat exchange device connects the air inlet of the flue of the second waste heat boiler unit to the exhaust port of the SCR denitrification reactor unit through the return flue. (II) The specific structure of the integrated heat exchange device. Specifically, the flue of the first waste heat boiler unit is vertically oriented, and its air inlet and exhaust outlet are located at different points in the upper and lower parts of the flue. An ash hopper is located at the lower part of the flue, and an ash discharge mechanism is connected to the bottom of the ash hopper. Similarly, the flue of the second waste heat boiler unit is vertically oriented, and its air inlet and exhaust outlet are located at different points in the upper and lower parts of the flue. Thus, the integrated heat exchange equipment forms an inverted U-shaped structure. Furthermore, the first waste heat boiler unit includes a first superheater, a first evaporator, and a first economizer arranged sequentially from front to back along the flue of the first waste heat boiler unit. The second waste heat boiler unit includes a second evaporator and a second economizer arranged sequentially from front to back along the flue of the second waste heat boiler unit. The steam drum correspondingly connected to the second evaporator (see attached instruction manual) Figure 3 As can be seen, the steam drum is part of the second waste heat boiler unit, while the first waste heat boiler unit also has a steam drum. The steam outlet of the steam drum is connected to the steam inlet of the first superheater via a steam transmission pipeline. The steam generated by the first superheater can be fed into a steam generator (turbine) to generate electricity.

[0004] During the implementation of the aforementioned industrial silicon smelting flue gas treatment system in the industrial silicon industrialization project, the applicant discovered the following problems: First, because the first waste heat boiler unit and the second waste heat boiler unit are arranged horizontally, this not only increases the horizontal footprint of the integrated heat exchange equipment, but more importantly, it also results in a horizontal distance between the supply flue and the return flue. Currently, the structure of integrated dust removal and denitrification equipment is relatively mature. The inlet (i.e., the inlet of the flue gas filter dust collector unit) and the outlet (i.e., the outlet of the SCR denitrification reactor unit) of such integrated dust removal and denitrification equipment are often arranged vertically. In other words, in order to adapt to the vertical arrangement of the inlet and outlet of the integrated dust removal and denitrification equipment, horizontally curved pipe sections must be installed on the supply flue and / or return flue, which leads to increased flue gas pressure loss and ash accumulation in the flue. In addition, it also limits the reduction of the distance between the integrated heat exchange equipment and the integrated dust removal and denitrification equipment, thereby increasing the layout length of the industrial silicon smelting flue gas treatment system. Secondly, to generate more high-quality steam for power generation, the steam outlet of the steam drum corresponding to the second evaporator was connected to the steam inlet of the first superheater via a steam pipeline. This would generate more high-pressure steam and increase power generation. However, further investigation revealed the following problems: In the initial operation of the industrial silicon smelting flue gas treatment system, the first waste heat boiler unit would first generate saturated steam. This saturated steam would flow to the second evaporator through the aforementioned steam pipeline, causing the first superheater to "dry burn," thus posing a safety hazard. Thirdly, the inventors also discovered that both the steam drums of the first and second waste heat boiler units perform gas-liquid separation and maintain a stable water level. When the steam outlet of the steam drum corresponding to the second evaporator is connected to the steam inlet of the first superheater via a steam pipeline, since only one type of high-pressure steam is ultimately generated, the independent design of the steam drums of the first and second waste heat boiler units is actually redundant. This not only leads to complicated control and piping layouts but also increases equipment investment and maintenance costs. Fourth, after the high-pressure steam generated by the waste heat boiler drives the steam generator to generate electricity, the steam is converted into condensate. The current conventional practice is to pass the condensate into a deaerator to remove oxygen and then return it to the waste heat boiler for recycling. Since the deaerator needs a heat source to heat the condensate, the current conventional solution is to draw some low-pressure steam from the steam generator as a heat source, but this practice will affect the power generation efficiency. Utility Model Content

[0005] The purpose of this invention is to provide an improved industrial kiln flue gas purification and waste heat utilization system and waste heat recovery device to solve the related problems mentioned in the background art.

[0006] In a first aspect, a flue gas purification and waste heat recovery system is provided, comprising: a first waste heat boiler unit for acquiring industrial kiln flue gas and performing first waste heat recovery before outputting first cooled flue gas; a flue gas filter dust collector unit for acquiring the first cooled flue gas and physically intercepting dust in the first cooled flue gas through a filter element before outputting first dust-removed flue gas; an SCR denitrification reactor unit for acquiring the first dust-removed flue gas with added SCR denitrification reducing agent and passing it through an SCR denitrification catalyst before outputting denitrified flue gas; and a second waste heat boiler unit for acquiring the denitrified flue gas and performing second waste heat recovery before outputting second cooled flue gas; wherein the first waste heat boiler unit and the second waste heat boiler unit are combined to form an integrated heat exchange device, the integrated heat exchange device having a first cooled flue gas exhaust port, a denitrified flue gas inlet port, and a second cooled flue gas exhaust port located in a first direction. The SCR denitrification reactor unit is assembled on the flue gas filter dust collector unit to form an integrated dust removal and denitrification device. The integrated dust removal and denitrification device has a first cooled flue gas inlet and a denitrified flue gas outlet located in the second direction. The integrated heat exchange device is arranged opposite to the integrated dust removal and denitrification device, with the first direction and the second direction being opposite directions. The first cooled flue gas outlet and the first cooled flue gas inlet are connected to a first cooled flue gas supply channel. The denitrified flue gas inlet and the denitrified flue gas outlet are connected to a denitrified flue gas return channel. The second cooled flue gas outlet is externally connected to a second cooled flue gas supply channel. Furthermore, the first waste heat boiler unit and the second waste heat boiler unit are arranged vertically overlapping each other. The first cooled flue gas supply channel, the denitrified flue gas return channel, and the second cooled flue gas supply channel each have transverse flues, which are arranged at intervals in the vertical direction.

[0007] Secondly, a waste heat recovery device is provided, comprising: a first waste heat boiler unit for acquiring industrial kiln flue gas and performing first waste heat recovery before outputting first cooled flue gas; a second waste heat boiler unit for acquiring the treated flue gas and performing second waste heat recovery before outputting second cooled flue gas, wherein the treated flue gas is formed by treating the first cooled flue gas; the first waste heat boiler unit and the second waste heat boiler unit are combined together to form an integrated heat exchange device; wherein the first waste heat boiler unit and the second waste heat boiler unit are arranged vertically overlapping each other.

[0008] The first and second waste heat boiler units are arranged in an overlapping manner, which not only helps to reduce the footprint of the flue gas purification and waste heat recovery system, but also helps to reduce the horizontal bends in the first cooled flue gas supply channel, the denitrified flue gas return channel, and the second cooled flue gas supply channel, thereby improving the flue gas pressure loss and ash collection problem. At the same time, this arrangement can better match the vertical layout characteristics of the dust removal and denitrification integrated equipment, making the flue layout simpler and more reasonable.

[0009] Thirdly, a flue gas purification and waste heat recovery system is provided, comprising: a first waste heat boiler unit for acquiring the industrial kiln flue gas and performing a first waste heat recovery before outputting a first cooled flue gas; a flue gas filter dust collector unit for acquiring the first cooled flue gas and physically intercepting the dust in the first cooled flue gas through a filter element before outputting a first dust-removed flue gas; an SCR denitrification reactor unit for acquiring the first dust-removed flue gas with added SCR denitrification reducing agent and outputting denitrified flue gas after passing through an SCR denitrification catalyst; and a second waste heat boiler unit for acquiring the denitrified flue gas and performing a second waste heat recovery before outputting a second cooled flue gas; wherein the first waste heat boiler unit and the second waste heat boiler unit are combined together to form an integrated heat exchange device; wherein the steam drum of the first waste heat boiler unit and the steam drum of the second waste heat boiler unit share the same steam drum, and the steam outlet of the steam drum is connected to the steam inlet of the superheater in the first waste heat boiler unit through a first steam delivery pipe.

[0010] Fourthly, a waste heat recovery device is provided, comprising: a first waste heat boiler unit for acquiring industrial kiln flue gas and performing first waste heat recovery before outputting first cooled flue gas; a second waste heat boiler unit for acquiring the treated flue gas and performing second waste heat recovery before outputting second cooled flue gas, wherein the treated flue gas is formed by treating the first cooled flue gas; the first waste heat boiler unit and the second waste heat boiler unit are combined together to form an integrated heat exchange device; wherein the steam drum of the first waste heat boiler unit and the steam drum of the second waste heat boiler unit share the same steam drum, and the steam outlet of the steam drum is connected to the steam inlet of the superheater in the first waste heat boiler unit through a first steam delivery pipe.

[0011] The design of the first and second waste heat boiler units sharing the same steam drum allows for stable system operation through unified water level and pressure control. This not only simplifies the system structure and control logic, reducing equipment investment and maintenance costs, but also makes the entire system more reliable and efficient.

[0012] Fifthly, a flue gas purification and waste heat recovery system is provided, comprising: a first waste heat boiler unit for acquiring the industrial kiln flue gas and performing a first waste heat recovery before outputting a first cooled flue gas; a flue gas filter dust collector unit for acquiring the first cooled flue gas and physically intercepting dust in the first cooled flue gas through a filter element before outputting a first dust-removed flue gas; an SCR denitrification reactor unit for acquiring the first dust-removed flue gas with added SCR denitrification reducing agent and outputting denitrified flue gas after passing through an SCR denitrification catalyst; and a second waste heat boiler unit for acquiring the denitrified flue gas and performing a second waste heat recovery before outputting a second cooled flue gas; wherein, the steam outlet of the steam drum corresponding to the first waste heat boiler unit is connected to the steam inlet of the superheater in the first waste heat boiler unit through a first steam conveying pipe, and the steam outlet of the steam drum corresponding to the second waste heat boiler unit is connected to the steam inlet of the superheater in the first waste heat boiler unit through a second steam conveying pipe; wherein, the second steam conveying pipe is provided with a steam flow direction control device for preventing the steam generated in the first waste heat boiler unit from flowing to the second waste heat boiler unit.

[0013] In a sixth aspect, a waste heat recovery device is provided, comprising: a first waste heat boiler unit for acquiring industrial kiln flue gas and performing a first waste heat recovery before outputting a first cooled flue gas; a second waste heat boiler unit for acquiring the treated flue gas and performing a second waste heat recovery before outputting a second cooled flue gas, wherein the treated flue gas is formed by treating the first cooled flue gas; wherein the steam outlet of the steam drum corresponding to the first waste heat boiler unit is connected to the steam inlet of the superheater in the first waste heat boiler unit via a first steam conveying pipe, and the steam outlet of the steam drum corresponding to the second waste heat boiler unit is connected to the steam inlet of the superheater in the first waste heat boiler unit via a second steam conveying pipe; the second steam conveying pipe is provided with a steam flow direction control device for preventing the steam generated in the first waste heat boiler unit from flowing to the second waste heat boiler unit.

[0014] A steam flow control device is installed on the second steam delivery pipe to prevent steam generated in the first waste heat boiler unit from flowing to the second waste heat boiler unit. This avoids the superheater in the first waste heat boiler unit from "dry burning" because the first waste heat boiler unit generates saturated steam first and then flows to the second waste heat boiler unit through the second steam delivery pipe during the initial operation of the system.

[0015] In a seventh aspect, a flue gas purification and waste heat recovery system is provided, comprising: a first waste heat boiler unit for acquiring the industrial kiln flue gas and performing first waste heat recovery before outputting first cooled flue gas; a flue gas filter dust collector unit for acquiring the first cooled flue gas and physically intercepting dust in the first cooled flue gas through a filter element before outputting first dust-removed flue gas; an SCR denitrification reactor unit for acquiring the first dust-removed flue gas with added SCR denitrification reducing agent and outputting denitrified flue gas after passing through an SCR denitrification catalyst; and a second waste heat boiler unit for acquiring the denitrified flue gas. After a second waste heat recovery, a second cooled flue gas is output; wherein, the steam generated by at least the first waste heat boiler unit becomes condensate after being powered by a steam generator, and the condensate is returned to the first waste heat boiler unit and / or the second waste heat boiler unit after being deaerated by a deaerator; in addition, a condensate heater is included to obtain the second cooled flue gas and use the second cooled flue gas to heat the condensate to become heated condensate, and the heated condensate is returned to the first waste heat boiler unit and / or the second waste heat boiler unit after being deaerated by a deaerator.

[0016] Eighthly, a waste heat recovery device is provided, comprising: a first waste heat boiler unit for acquiring industrial kiln flue gas and performing first waste heat recovery before outputting first cooled flue gas; a second waste heat boiler unit for acquiring the treated flue gas and performing second waste heat recovery before outputting second cooled flue gas, wherein the treated flue gas is formed by treating the first cooled flue gas; steam generated by at least the first waste heat boiler unit is converted into condensate by a steam generator, and the condensate is deoxygenated by a deaerator and returned to the first waste heat boiler unit and / or the second waste heat boiler unit; a condensate heater is further provided in the end section of the flue of the second waste heat boiler unit, wherein the condensate heater is used to acquire the second cooled flue gas and use the second cooled flue gas to heat the condensate into heated condensate, and the heated condensate is deoxygenated by a deaerator and returned to the first waste heat boiler unit and / or the second waste heat boiler unit.

[0017] By adding a condensate heater and using the second cooled flue gas to preheat the condensate, not only is the waste heat of the second cooled flue gas further recovered and utilized, but the temperature of the heated condensate entering the deaerator is also increased. This can reduce or even eliminate the independent heating of the deaerator and reduce the impact on power generation efficiency caused by drawing some low-pressure steam from the steam generator as a heat source to heat the deaerator.

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice. Attached Figure Description

[0019] The accompanying drawings, which form part of this specification, are used to aid in understanding the present invention. The contents provided in the drawings and their related descriptions in this specification can be used to explain the present invention, but do not constitute an undue limitation on the present invention.

[0020] Figure 1 This is a schematic diagram of the structure of a flue gas purification and waste heat recovery system according to an embodiment of the present invention.

[0021] Figure 2 for Figure 1 A side view of the integrated heat exchanger that appears in the image.

[0022] Figure 3 This is a schematic diagram of a waste heat recovery device according to an embodiment of the present utility model.

[0023] Figure 4 This is a schematic diagram of a waste heat recovery device according to an embodiment of the present utility model. Detailed Implementation

[0024] The present invention will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0025] The technical solutions and features provided in the various sections, including the following description, can be combined with each other without conflict. Furthermore, where possible, these technical solutions, features, and related combinations can be given specific technical subject matter and protected by relevant patents.

[0026] The embodiments of the present invention described below are generally only some embodiments and not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of patent protection.

[0027] Regarding the terminology and units in this specification: The terms "comprising," "including," "having," and any variations thereof in this specification, the corresponding claims, and related sections are intended to cover non-exclusive inclusion. Furthermore, other related terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0028] Figure 1 This is a schematic diagram of the structure of a flue gas purification and waste heat recovery system according to an embodiment of the present invention. Figure 2 for Figure 1 A side view of the integrated heat exchanger that appears in the image. Figure 4 This is a schematic diagram of a waste heat recovery device according to an embodiment of the present utility model. Figure 1 The flue gas purification and waste heat recovery system shown adopts Figure 4 Waste heat recovery device in the middle.

[0029] like Figures 1-2 as well as Figure 4 As shown, an embodiment of the present invention provides a flue gas purification and waste heat recovery system, comprising: a first waste heat boiler unit 11, used to acquire industrial kiln flue gas (specifically, high-temperature flue gas emitted from an industrial silicon smelting furnace) and perform first waste heat recovery before outputting first cooled flue gas; a flue gas filter dust collector unit 21, used to acquire the first cooled flue gas and physically intercept dust in the first cooled flue gas through a filter element before outputting first dust-removed flue gas; an SCR denitrification reactor unit 22, used to acquire the first dust-removed flue gas with added SCR denitrification reducing agent and output denitrified flue gas after passing through an SCR denitrification catalyst; and a second waste heat boiler unit 12, used to acquire the denitrified flue gas and perform second waste heat recovery before outputting second cooled flue gas.

[0030] The first waste heat boiler unit 11 and the second waste heat boiler unit 12 are combined together to form an integrated heat exchange device 1 (i.e., a waste heat recovery device). The integrated heat exchange device 1 has a first cooled flue gas exhaust port, a denitrified flue gas inlet, and a second cooled flue gas exhaust port located in a first direction.

[0031] The SCR denitrification reactor unit 22 is assembled on the flue gas filter dust collector unit 21 to form an integrated dust removal and denitrification device 2. The integrated dust removal and denitrification device 2 has a first cooled flue gas inlet and a denitrified flue gas exhaust outlet located in the second direction.

[0032] The integrated heat exchanger 1 and the integrated dust removal and denitrification equipment 2 are arranged opposite each other, with the first direction and the second direction being opposite directions. The first cooled flue gas exhaust port and the first cooled flue gas inlet are connected to a first cooled flue gas supply channel 31, and the denitrified flue gas inlet and the denitrified flue gas exhaust port are connected to a denitrified flue gas return channel 32. The second cooled flue gas exhaust port is externally connected to a second cooled flue gas supply channel 33. The second cooled flue gas supply channel 33 can be connected to the desulfurization unit.

[0033] Furthermore, the first waste heat boiler unit 11 and the second waste heat boiler unit 12 are arranged vertically overlapping each other. The first cooled flue gas supply channel 31, the denitrified flue gas return channel 32 and the second cooled flue gas supply channel 33 each have transverse flues (i.e. horizontal flues), and these transverse flues are arranged at intervals in the vertical direction.

[0034] Specifically, the first waste heat boiler unit 11 is located above the second waste heat boiler unit 12, the first cooled flue gas exhaust port is located above the denitrified flue gas inlet, and the second cooled flue gas exhaust port is located below the denitrified flue gas inlet. The denitrified flue gas inlet and the denitrified flue gas exhaust port are at the same height. In addition, the transverse flue of the first cooled flue gas supply channel 31 is connected to the first cooled flue gas exhaust port through a longitudinally offset flue 34 (the longitudinally offset flue 34 bypasses the denitrified flue gas return channel 32) located next to the denitrified flue gas inlet. The transverse flue of the denitrified flue gas return channel 32 (the denitrified flue gas return channel 32 is entirely transverse) is directly aligned with and connected to the denitrified flue gas inlet. The transverse flue of the second cooled flue gas supply channel 33 is directly aligned with and connected to the second cooled flue gas exhaust port.

[0035] The first waste heat boiler unit 11 and the second waste heat boiler unit 12 are arranged in an overlapping manner, which not only helps to reduce the footprint of the flue gas purification and waste heat recovery system, but also helps to reduce the horizontal bends in the first cooled flue gas supply channel 31, the denitrified flue gas return channel 32, and the second cooled flue gas supply channel 33, thereby improving flue gas pressure loss and ash accumulation. At the same time, this arrangement can better match the vertical layout of the inlet and outlet of the integrated dust removal and denitrification equipment 2, making the flue layout simpler and more reasonable. The distance between the integrated heat exchange equipment 1 and the integrated dust removal and denitrification equipment 2 is very short, which can greatly save the footprint of the flue gas purification and waste heat recovery system.

[0036] As a specific embodiment of the above-mentioned integrated dust removal and denitrification equipment 2, the integrated dust removal and denitrification equipment includes:

[0037] A) A first enclosure, the first enclosure having internal compartments formed by a partition system within the first enclosure:

[0038] A1) The left dust collector main body has one or more left dust collector compartments arranged sequentially in the front-to-back direction. Each left dust collector compartment has a lower raw air chamber and an upper clean air chamber. A filter element mounting plate is provided between the lower raw air chamber and the upper clean air chamber. A filter element extending downward into the lower raw air chamber of the left dust collector is installed on the filter element mounting plate.

[0039] A2) Right-side dust collector main body, the right-side dust collector main body has one or more right-side dust collector compartments arranged sequentially in the front-back direction, each right-side dust collector compartment has a lower raw air chamber and an upper clean air chamber, a filter element mounting plate is provided between the lower raw air chamber and the upper clean air chamber, and a filter element extending downward into the lower raw air chamber of the left-side dust collector is installed on the filter element mounting plate;

[0040] A3) Intermediate flue gas compartment, which is located between the left dust collector compartment and the right dust collector compartment and has a lower air intake flue gas compartment and an upper exhaust flue gas compartment. The lower air intake flue gas compartment extends in the front-to-back direction and is connected to the lower original air compartment of each left dust collector and the lower original air compartment of each right dust collector. The upper exhaust flue gas compartment extends in the front-to-back direction.

[0041] B) A second enclosure, which is disposed on top of the first enclosure and has a passage reserved around the perimeter of the second enclosure on the top surface of the first enclosure. The second enclosure has the following compartments formed by internal partitions:

[0042] B1) The lower part of the left air collection chamber is located above the main body of the left dust collector and is connected to the upper clean air chamber of each left dust collector. The upper right side partition of the left air collection chamber is provided with an upper exhaust port of the left air collection chamber.

[0043] B2) Right side air collection chamber, the lower part of which is located above the main body of the right side dust collector and is connected to the upper clean air chamber of each right side dust collector. The upper left side partition of the right side air collection chamber is provided with an upper exhaust port of the right side air collection chamber.

[0044] B3) Intermediate SCR denitrification reaction chamber, which is located between the left gas collection chamber and the right gas collection chamber. The upper part of the intermediate SCR denitrification reaction chamber is connected to the upper exhaust port of the left gas collection chamber and the upper exhaust port of the right gas collection chamber, respectively. The lower part of the intermediate SCR denitrification reaction chamber is located above the intermediate flue chamber and is connected to the upper exhaust flue chamber. An SCR denitrification catalyst bed is provided in the intermediate SCR denitrification reaction chamber.

[0045] The main air inlet of the lower air intake flue compartment and the main exhaust outlet of the upper exhaust flue compartment are arranged on the same side in the front-rear direction of the first housing and face the second direction.

[0046] The aforementioned integrated dust removal and denitrification equipment 2 features a combination of a large housing (first housing) and a small housing (second housing), with the small housing located on top of the large housing. While the internal structure of the large housing is relatively common, the key innovation lies in the internal structure of the small housing and its connection to the large housing. The small housing utilizes the left and right gas collection chambers to draw airflow from the upper clean air chambers of each left and right dust collector upwards. The airflow then flows downwards through the intermediate SCR denitrification reaction chamber. The airflow exiting the intermediate SCR denitrification reaction chamber continues downwards into the upper exhaust flue chamber, ultimately exiting the integrated dust removal and denitrification equipment 2 through the upper exhaust flue chamber. This integrated dust removal and denitrification equipment 2 directly utilizes the upper exhaust flue chamber within the large housing for exhaust, achieving an integrated dust removal and denitrification solution through simple modifications to the existing dust collector structure. In addition to its simple structure and reduced construction costs, the above-mentioned integrated dust removal and denitrification equipment 2 also has the advantages of convenient loading and unloading of SCR denitrification catalyst and saving floor space.

[0047] As another specific embodiment of the above-mentioned integrated dust removal and denitrification equipment 2 structure (disclosed in patent document CN118391924A), the integrated dust removal and denitrification equipment includes:

[0048] A) A first enclosure, the first enclosure having internal compartments formed by a partition system within the first enclosure:

[0049] A1) The left dust collector main body has one or more left dust collector compartments arranged sequentially in the front-to-back direction. Each left dust collector compartment has a lower raw air chamber and an upper clean air chamber. A filter element mounting plate is provided between the lower raw air chamber and the upper clean air chamber. A filter element extending downward into the lower raw air chamber of the left dust collector is installed on the filter element mounting plate.

[0050] A2) Right-side dust collector main body, the right-side dust collector main body has one or more right-side dust collector compartments arranged sequentially in the front-back direction, each right-side dust collector compartment has a lower raw air chamber and an upper clean air chamber, a filter element mounting plate is provided between the lower raw air chamber and the upper clean air chamber, and a filter element extending downward into the lower raw air chamber of the left-side dust collector is installed on the filter element mounting plate;

[0051] A3) Intermediate flue gas compartment, located between the left and right dust collector compartments, and comprising a lower intake flue gas compartment and an upper clean air conveying compartment. The lower intake flue gas compartment extends in the front-to-back direction and is connected to the lower original air compartments of each left and right dust collector. The upper clean air conveying compartment is located above the lower intake flue gas compartment, extends in the front-to-back direction, and is connected to the upper clean air compartments of each left and right dust collector. The intermediate flue gas compartment also comprises a middle exhaust flue gas compartment located between the lower intake flue gas compartment and the upper clean air conveying compartment. The middle exhaust flue gas compartment extends in the front-to-back direction. The lower exhaust port of the rear SCR denitrification reaction chamber is connected to the rear end of the middle exhaust flue gas compartment. The total air inlet of the lower intake flue gas compartment and the total exhaust port of the middle exhaust flue gas compartment are arranged on the same side of the first housing.

[0052] B) A second enclosure, disposed at the rear of the first enclosure, wherein the interior of the second enclosure has the following compartments formed by a partition system within the second enclosure:

[0053] B1) Front gas collection chamber, the lower part of which is located at the rear of the upper clean gas delivery chamber and communicates with the upper clean gas delivery chamber, and the upper part of which is provided with an upper exhaust port.

[0054] B2) Rear SCR denitrification reaction chamber, wherein the rear SCR denitrification reaction chamber is located at the rear of the front gas collection chamber, the upper part of the rear SCR denitrification reaction chamber is connected to the upper exhaust port of the front gas collection chamber, the lower part of the rear SCR denitrification reaction chamber is provided with a lower exhaust port, and an SCR denitrification catalyst bed is provided in the rear SCR denitrification reaction chamber;

[0055] The main air inlet of the lower air intake flue compartment and the main exhaust outlet of the middle exhaust flue compartment are arranged on the same side of the first housing and face the second direction.

[0056] The integrated dust removal and denitrification equipment 2 features a combination of a large housing (first housing) and a small housing (second housing), with the small housing located at the rear of the large housing. A key innovation of this integrated dust removal and denitrification equipment is the connection between the upper clean air delivery chamber of the large housing and the small housing. Because the small housing is located at the rear of the large housing, the large housing does not need to bear the weight of the small housing. The large housing guides the airflow into the small housing through the upper clean air delivery chamber, simply achieving communication between the two housings. The advantages of this integrated dust removal and denitrification equipment include simple structure and reduced construction costs.

[0057] It should be noted that the specific implementation methods of the above two integrated dust removal and denitrification devices have been disclosed and described in the applicant's earlier patent application, application number 2024215950909. If the specific implementation methods of the above two integrated dust removal and denitrification devices are unclear, please refer to that earlier application.

[0058] Each of the left-side dust collectors and the right-side dust collectors has a dust hopper at the bottom of its original air chamber, and each dust hopper has a dust discharge device at the bottom.

[0059] The transverse flue of the second cooled flue gas delivery channel 33 is arranged between a row of ash hoppers formed by the ash hoppers at the bottom of the original gas chambers at the bottom of each left-side dust collector and another row of ash hoppers formed by the ash hoppers at the bottom of the original gas chambers at the bottom of each right-side dust collector.

[0060] In addition, a flue support 4 is provided between the integrated heat exchanger 1 and the integrated dust removal and denitrification equipment 2. The transverse flue of the first cooled flue gas supply channel, the transverse flue of the denitrified flue gas return channel, and the transverse flue of the second cooled flue gas supply channel are respectively mounted on support platforms of different heights on the flue support 4.

[0061] like Figures 1-2 as well as Figure 4 As shown, in the waste heat recovery device here, the steam drum 111 of the first waste heat boiler unit 11 and the steam drum of the second waste heat boiler unit 12 share the same steam drum 111. The steam outlet of the steam drum 111 is connected to the steam inlet of the superheater 113 in the first waste heat boiler unit 11 through the first steam conveying pipe 112.

[0062] Previously, the steam drum 111 of the first waste heat boiler unit 11 and the steam drum of the second waste heat boiler unit 12 were independent (see...). Figure 3 The inventors discovered that both the steam drums of the first and second waste heat boiler units perform gas-liquid separation and maintain a stable water level. When the steam outlet of the corresponding steam drum connected to the second evaporator is connected to the steam inlet of the first superheater through a steam transmission pipeline, since only one type of high-pressure steam is ultimately produced, the independent design of the steam drums of the first and second waste heat boiler units is actually redundant. This not only leads to complicated control and piping layout but also increases equipment investment and maintenance costs. Figure 4 In this system, because the first and second waste heat boiler units share the same steam drum design, stable system operation can be achieved through unified water level and pressure control. This simplifies the system structure and control logic, reduces equipment investment and maintenance costs, and makes the entire system more reliable and efficient.

[0063] In addition, such as Figure 4 As shown, a one-way valve 122 is provided on the riser pipe of the evaporator 121 in the second waste heat boiler unit 12 to prevent water vapor in the steam drum 111 from flowing to the second waste heat boiler unit 12 through the riser pipe. This prevents the saturated steam in the steam drum 111 from flowing to the second waste heat boiler unit during the initial stage of system operation, which could cause the superheater 113 in the first waste heat boiler unit to "dry burn".

[0064] The steam generated by the first waste heat boiler unit 11 and the second waste heat boiler unit 12 is all turned into condensate after being powered by the steam generator 5. The condensate needs to be deoxygenated by the deaerator before being returned to the first waste heat boiler unit and the second waste heat boiler unit.

[0065] like Figure 4 As shown, in the waste heat recovery device, the hot surface (i.e., the heating surface) of the first waste heat boiler unit 11 is composed of a superheater 113 and an evaporator 114 arranged sequentially along the flue gas flow direction; the hot surface of the second waste heat boiler unit 12 is composed of an evaporator 121, an economizer 123 and a condensate heater 124 arranged sequentially along the flue gas flow direction.

[0066] The condensate heater 124 is used to obtain the second cooled flue gas and use the second cooled flue gas to heat the condensate to become heated condensate. The heated condensate is then deoxygenated by the deaerator 7 and returned to the first waste heat boiler unit and the second waste heat boiler unit.

[0067] Previously, after the high-pressure steam generated by the waste heat boiler drives the steam generator to generate electricity, the steam is converted into condensate. The conventional approach is to pass the condensate into a deaerator for deoxygenation and then return it to the waste heat boiler for recycling. Since the deaerator requires a heat source to heat the condensate, the conventional solution is to draw some low-pressure steam from the steam generator as a heat source, which affects power generation efficiency. Here, by adding a condensate heater 124, the condensate is preheated using the second cooled flue gas. This not only achieves further recovery and utilization of the waste heat of the second cooled flue gas, but also increases the temperature of the heated condensate entering the deaerator 6. It can reduce or even eliminate the independent heating of the deaerator, and reduce the impact of drawing some low-pressure steam from the steam generator as a heat source for heating the deaerator on power generation efficiency. Here, the condensate heater 124 is set in the end section of the flue of the second waste heat boiler unit, becoming part of the hot surface of the second waste heat boiler unit, which is the most ideal installation position for the condensate heater 124.

[0068] like Figure 4 As shown, a condensate storage tank 7 is provided between the steam generator 5 and the condensate heater 124 to better supply condensate to the condensate heater 124.

[0069] Figure 3 This is a schematic diagram of a waste heat recovery device according to an embodiment of the present utility model. Figure 1 The flue gas purification and waste heat recovery system shown can also be used Figure 3 Waste heat recovery device in the middle.

[0070] like Figure 3 As shown, the steam outlet of the steam drum 111 corresponding to the first waste heat boiler unit 11 is connected to the steam inlet of the superheater 113 in the first waste heat boiler unit 11 through the first steam conveying pipe 112, and the steam outlet of the steam drum 125 corresponding to the second waste heat boiler unit 12 is connected to the steam inlet of the superheater 113 in the first waste heat boiler unit 11 through the second steam conveying pipe 125; wherein, the second steam conveying pipe 125 is provided with a steam flow direction control device to prevent the steam generated in the first waste heat boiler unit 11 from flowing to the second waste heat boiler unit 12.

[0071] Specifically, the steam flow direction control device adopts a one-way valve 126; the outlet of the second steam delivery pipe 125 is connected to the first steam delivery pipe 112.

[0072] A steam flow control device is installed on the second steam conveying pipe 125 to prevent the steam generated in the first waste heat boiler unit 11 from flowing to the second waste heat boiler unit 12. This avoids the superheater 113 in the first waste heat boiler unit 11 from "dry burning" because the first waste heat boiler unit 11 generates saturated steam first and then flows to the second waste heat boiler unit 12 through the second steam conveying pipe 125 during the initial operation of the system.

[0073] like Figure 3 As shown, in the waste heat recovery device here, the hot surface (i.e., the heating surface) of the first waste heat boiler unit 11 is composed of a superheater 113 and an evaporator 114 arranged sequentially along the flue gas flow direction; the hot surface of the second waste heat boiler unit 12 is composed of an evaporator 121, an economizer 123 and a condensate heater 124 arranged sequentially along the flue gas flow direction.

[0074] The condensate heater 124 is used to obtain the second cooled flue gas and use the second cooled flue gas to heat the condensate output by the steam generator 5 to become heated condensate. The heated condensate is then deoxygenated by the deaerator 7 and returned to the first waste heat boiler unit and the second waste heat boiler unit.

[0075] By using the condensate heater 124 to preheat the condensate with the second cooled flue gas, not only is the waste heat of the second cooled flue gas further recovered and utilized, but the temperature of the heated condensate entering the deaerator 6 is also increased. This can reduce or even eliminate the independent heating of the deaerator, and reduce the impact on power generation efficiency caused by drawing some low-pressure steam from the steam generator as a heat source to heat the deaerator.

[0076] The foregoing has described the relevant content of this utility model. Those skilled in the art will be able to implement this utility model based on these descriptions. All other embodiments obtained by those skilled in the art based on the foregoing content of this specification without inventive effort should fall within the scope of patent protection.

Claims

1. A flue gas cleaning and waste heat recovery system, comprising: a first waste heat boiler unit for obtaining industrial kiln flue gas and outputting first cooled flue gas after first waste heat recovery; a flue gas filter dust remover unit for obtaining the first cooled flue gas and outputting first dedusted flue gas after physically intercepting dust in the first cooled flue gas by a filter core; an SCR denitration reactor unit for obtaining the first dedusted flue gas added with an SCR denitration reducing agent and outputting denitration flue gas after passing through an SCR denitration catalyst; a second waste heat boiler unit for obtaining the denitration flue gas and outputting second cooled flue gas after second waste heat recovery; wherein water vapor generated by at least the first waste heat boiler unit among the first waste heat boiler unit and the second waste heat boiler unit becomes condensed water after work by a steam generator, and the condensed water returns to the first waste heat boiler unit and / or the second waste heat boiler unit after deaeration by a deaerator; characterized in that: a condensed water heater is arranged for obtaining the second cooled flue gas and heating the condensed water into heated condensed water by using the second cooled flue gas, and the heated condensed water returns to the first waste heat boiler unit and / or the second waste heat boiler unit after deaeration by a deaerator.

2. The flue gas cleaning and heat recovery system according to claim 1, characterized in that: The condensed water heater is arranged in a final section of a flue duct of the second waste heat boiler unit and becomes part of a heat exchange surface of the second waste heat boiler unit.

3. The flue gas cleaning and heat recovery system according to claim 2, characterized in that: The heat surface of the second waste heat boiler unit is composed of an evaporator, an economizer and the condensed water heater arranged in sequence along a flue gas flow direction.

4. The flue gas cleaning and heat recovery system according to claim 1, wherein: The heat surface of the first waste heat boiler unit is composed of a superheater and an evaporator arranged in sequence along a flue gas flow direction.

5. The flue gas cleaning and heat recovery system according to claim 1, wherein: The first waste heat boiler unit and the second waste heat boiler unit are combined together so that the first waste heat boiler unit and the second waste heat boiler unit form an integrated heat exchange device.

6. The flue gas cleaning and heat recovery system according to claim 5, wherein: A drum of the first waste heat boiler unit and a drum of the second waste heat boiler unit share a same drum, and a water vapor outlet of the drum is connected to a water vapor inlet of the superheater in the first waste heat boiler unit through a first steam delivery pipe.

7. The flue gas cleaning and heat recovery system according to claim 5, wherein: The integrated heat exchange device has a first cooled flue gas exhaust port, a denitration flue gas inlet port and a second cooled flue gas exhaust port in a first direction. The SCR denitration reactor unit is assembled on the flue gas filter dust remover unit to form a dedusting and denitration integrated device, and the dedusting and denitration integrated device has a first cooled flue gas inlet port and a denitration flue gas exhaust port in a second direction. The integrated heat exchange device and the dedusting and denitration integrated device are arranged oppositely, the first direction and the second direction are opposite directions, a first cooled flue gas delivery channel is connected between the first cooled flue gas exhaust port and the first cooled flue gas inlet port, a denitration flue gas return channel is connected between the denitration flue gas inlet port and the denitration flue gas exhaust port, and a second cooled flue gas delivery channel is circumscribed by the second cooled flue gas exhaust port. The first waste heat boiler unit and the second waste heat boiler unit are arranged in a vertical direction.

8. The flue gas cleaning and heat recovery system according to claim 7, characterized in that: The first waste heat boiler unit is arranged above the second waste heat boiler unit, the first cooled flue gas outlet is arranged above the denitration flue gas inlet, and the second cooled flue gas outlet is arranged below the denitration flue gas inlet. The lateral flue of the first cooled flue gas feeding passage is connected to the first cooled flue gas outlet through a longitudinal offset flue arranged beside the denitration flue gas inlet, the lateral flue of the denitration flue gas return passage is directly connected to the denitration flue gas inlet, and the lateral flue of the second cooled flue gas feeding passage is directly connected to the second cooled flue gas outlet.

9. The flue gas cleaning and heat recovery system according to claim 1, wherein: A condensate storage is arranged between the steam generator and the condensate heater.

10. A waste heat recovery device, comprising: a first waste heat boiler unit for obtaining flue gas of an industrial kiln and outputting first cooled flue gas after first waste heat recovery; a second waste heat boiler unit for obtaining treated flue gas and outputting second cooled flue gas after second waste heat recovery, the treated flue gas being formed by the first cooled flue gas after flue gas treatment; characterized in that: water vapor generated by at least the first waste heat boiler unit becomes condensate after work of a steam generator, and the condensate returns to the first waste heat boiler unit and / or the second waste heat boiler unit after deaeration by a deaerator; a condensate heater is arranged in a terminal section of a flue of the second waste heat boiler unit, the condensate heater is used for obtaining the second cooled flue gas and heating the condensate to heated condensate by using the second cooled flue gas, and the heated condensate returns to the first waste heat boiler unit and / or the second waste heat boiler unit after deaeration by a deaerator.

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