Flue gas denitration system

Abstract

The utility model relates to the field of flue gas treatment, in particular to a flue gas denitration system, which comprises an air preheater, a denitration device and a denitration device, the air preheater is used for heating input air to obtain hot air, and a pressure sensor is arranged on the air preheater and used for monitoring the pressure value of the hot air; the flue gas denitration part is used for carrying out denitration on the flue gas based on the hot air; the air supply part is connected with the air preheater and the flue gas denitration part, the air supply part comprises a first pipeline and a second pipeline, the first pipeline is used for conveying hot air to the flue gas denitration part through the first pipeline when the pressure value of the hot air reaches a preset value, and the second pipeline comprises a water cooling fan; and the second pipeline is used for conveying the hot air passing through the water cooling fan to the flue gas denitration part when the pressure value of the hot air does not reach a preset value. According to the utility model, the safe and stable operation of the flue gas denitration system is ensured, the consumption of the dilution fan by the flue gas consumption system is reduced, and the denitration efficiency of the flue gas denitration system is improved.

Description

Technical Field

[0001] The utility model relates to the field of flue gas treatment, in particular to a flue gas denitrification system. Background Art

[0002] Boiler flue gas contains nitrogen oxides, which are important pollutants produced during the combustion process and have serious negative impacts on the environment. Therefore, in the process of using boilers for smelting, it is necessary to denitrify the flue gas.

[0003] The existing boiler flue gas denitrification system uses two dilution fans to draw hot air from the hot air box at the outlet of the air preheater to the ammonia evaporator, evaporates the ammonia water into ammonia gas, and then denitrates the flue gas. During the flue gas denitrification process, if the dilution fan is burned by the hot air, it cannot be detected in time. In addition, during the flue gas denitrification process, if both dilution fans are online, if one or both dilution fans fail, the safe and stable operation of the denitrification system will be affected, and the denitrification efficiency of the denitrification system will be reduced due to the inability to replace the dilution fan in time.

[0004] Based on this, the existing technology still needs to be improved. Utility Model Content

[0005] One of the technical problems to be solved by the utility model is how to improve the existing flue gas denitrification system to ensure the safe and stable operation of the flue gas denitrification system and to improve the denitrification efficiency of the flue gas denitrification system.

[0006] In order to solve the above technical problems, some embodiments of the present utility model disclose a flue gas denitrification system, which includes:

[0007] Air preheater, which is used to heat the input air to obtain hot air. The air preheater is provided with a pressure sensor to monitor the pressure value of the hot air;

[0008] Flue gas denitrification unit, used for denitrifying flue gas based on hot air;

[0009] Air supply section, which is connected to the air preheater and the flue gas denitrification section. The air supply section includes:

[0010] The first pipeline is used to transport the hot air to the flue gas denitrification part when the pressure value of the hot air reaches a preset value.

[0011] The second pipeline includes a water-cooled fan, and the second pipeline is used to transport the hot air that has passed through the water-cooled fan to the flue gas denitrification part when the pressure value of the hot air does not reach a preset value.

[0012] In some embodiments, the first pipeline includes a first valve, and the first valve is used to be in an open state when the pressure value of the hot air reaches a preset value, and to be in a closed state when the pressure value of the hot air does not reach the preset value.

[0013] In some embodiments, the first valve is an electric valve.

[0014] In some embodiments, the second pipeline includes a second valve, which is connected to the water-cooling fan. The second valve is used to be in an open state when the pressure value of the hot air does not reach a preset value.

[0015] In some embodiments, the number of the second valves is one or more, and the multiple second valves are sequentially connected to the water-cooling fan or partially arranged on both sides of the water-cooling fan.

[0016] In some embodiments, the water-cooling fan is further configured to be in a closed state when the pressure value of the hot air reaches a preset value, and to be in an open state when the pressure value of the hot air does not reach the preset value.

[0017] In some embodiments, the number of the first valve is 1 or more.

[0018] In some embodiments, the flue gas denitrification unit includes:

[0019] Ammonia injection pipeline, used to input ammonia water;

[0020] The ammonia evaporator is connected to the air supply unit and the ammonia spraying pipeline, and is used to evaporate the ammonia water into ammonia gas based on the hot air output from the air supply unit and output it.

[0021] In some embodiments, the flue gas denitrification unit further includes:

[0022] The SCR reactor is connected to the ammonia evaporator and is used for reacting ammonia outputted from the ammonia evaporator with flue gas to denitrate the flue gas.

[0023] In some embodiments, the preset value is 1 kPa.

[0024] By adopting the above technical solution, the utility model has at least the following beneficial effects:

[0025] The utility model provides a flue gas denitrification system, comprising an air preheater, a flue gas denitrification unit and an air supply unit, wherein the air preheater is used to heat input air to obtain hot air and monitor the pressure value of the hot air, the flue gas denitrification unit is used to denitrify the flue gas based on the hot air, the air supply unit is connected with the air preheater and the flue gas denitrification unit, the air supply unit comprises a first pipeline and a second pipeline, the second pipeline comprises a water-cooled fan, the second pipeline is used to transport the hot air that has passed through the water-cooled fan to the flue gas denitrification unit when the pressure value of the hot air does not reach a preset value, and the first pipeline is used to transport the hot air to the flue gas denitrification unit when the pressure value of the hot air reaches a preset value. In the above-mentioned flue gas denitrification system, a water-cooled fan is used as a dilution fan, which can effectively reduce the risk of burning of the traditional dilution fan by hot air. At the same time, only one of the two channels of the air supply part is connected to the water-cooled fan, that is, only one water-cooled fan is online, and the other water-cooled fan can be used as an offline standby water-cooled fan, and is adaptively transported to the flue gas denitrification part through one of the channels according to the real-time pressure value of the hot air. This is beneficial to ensure the safe and stable operation of the flue gas denitrification system, reduce the consumption of the dilution fan by the flue gas consumption system, and help improve the air supply efficiency of the flue gas denitrification system, thereby improving the denitrification efficiency of the flue gas denitrification system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of a flue gas denitrification system disclosed in some embodiments of the utility model;

[0028] Figure 2 Another schematic diagram of a flue gas denitrification system disclosed in some embodiments of the utility model;

[0029] Figure 3 It is a structural schematic diagram of a flue gas denitrification system disclosed in the prior art.

[0030] Description of reference numerals:

[0031] 1. Air preheater; 2. Pressure sensor; 3. Flue gas denitrification unit; 4. Air supply unit; 5. First pipeline; 6. Second pipeline; 7. Water-cooled fan; 8. First valve; 9. Second valve; 10. Ammonia injection pipeline; 11. Ammonia evaporator; 12. SCR reactor; 13. First pipeline; 14. Second pipeline; 15. First valve; 16. Second valve; 17. Dilution fan; 100. Flue gas denitrification system. DETAILED DESCRIPTION

[0032] The following is a further detailed description of the embodiments of the present disclosure in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present disclosure, but cannot be used to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

[0033] The present disclosure provides these embodiments to make the present disclosure thorough and complete, and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary, and not as limiting.

[0034] It should be noted that, in the description of the present disclosure, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0035] In addition, the words "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" does not mean vertical in the strict sense, but is within the tolerance range. "Parallel" does not mean parallel in the strict sense, but is within the tolerance range. "Include" or "comprising" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.

[0036] It should also be noted that in the description of the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.

[0037] All terms used in the present disclosure have the same meanings as those understood by those of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, for example, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined as such herein.

[0038] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0039] like Figure 1-2 As shown, some embodiments of the utility model disclose a flue gas denitration system 100, including an air preheater 1, a flue gas denitration unit 3 and an air supply unit 4, the air preheater 1 is used to heat the input air to obtain hot air, and the air preheater 1 is provided with a pressure sensor 2, the pressure sensor 2 is used to monitor the pressure value of the hot air; the flue gas denitration unit 3 is used to denitrate the flue gas based on the hot air; the air supply unit 4 is connected to the air preheater 1 and the flue gas denitration unit 3, the air supply unit 4 includes a first pipeline 5 and a second pipeline 6, the first pipeline 5 is used to transport the hot air to the flue gas denitration unit 3 when the pressure value of the hot air reaches a preset value, the second pipeline 6 includes a water-cooled fan 7, and the second pipeline 6 is used to transport the hot air passing through the water-cooled fan 7 to the flue gas denitration unit 3 when the pressure value of the hot air does not reach the preset value. Among them, the bearings of the water-cooled fan 7 are cooled by water, which can effectively prevent the heat from being transferred to the motor and causing the motor to burn out.

[0040] The above-mentioned flue gas denitrification system 100 adopts the water-cooled fan 7 as the dilution fan, which can effectively reduce the risk of burning the traditional dilution fan by hot air. At the same time, only one of the two channels of the air supply part 4 is connected to the water-cooled fan 7, that is, only one water-cooled fan 7 is online, and the other water-cooled fan 7 can be used as an offline standby water-cooled fan, and is adaptively transported to the flue gas denitrification part 3 through one of the channels according to the real-time pressure value of the hot air, which is beneficial to ensure the safe and stable operation of the flue gas denitrification system 100, reduce the consumption of the dilution fan by the flue gas consumption system 100, and help improve the air supply efficiency of the flue gas denitrification system 100, thereby improving the denitrification efficiency of the flue gas denitrification system 100.

[0041] In some embodiments, please refer to Figure 2The first pipeline 5 includes a first valve 8, which is used to be in an open state when the pressure value of the hot air reaches a preset value, and in a closed state when the pressure value of the hot air does not reach the preset value. The preset value is a hot gas pressure threshold value determined according to the actual process flow. If the hot gas pressure threshold value is reached, it means that the hot gas can be automatically transported from the air preheater 1 to the flue gas denitrification part 3 through the first pipeline 5, so it is necessary to open the first valve 8 on the first pipeline 5; if the hot gas pressure threshold value is not reached, it means that the hot gas cannot be automatically transported from the air preheater 1 to the flue gas denitrification part 3 through the first pipeline 5, so it is necessary to close the first valve 8 on the first pipeline 5, so that the hot gas is transported to the flue gas denitrification part 3 through the second pipeline 6 and the water-cooled fan 7 on the second pipeline 6.

[0042] In some embodiments, the first valve 8 is an electric valve.

[0043] In some embodiments, please refer to Figure 2 The second pipeline 6 includes a second valve 9, which is connected to the water-cooled fan 7. The second valve 9 is used to be in an open state when the pressure value of the hot air does not reach a preset value. The preset value is a hot gas pressure threshold determined according to the actual process flow. If the actual pressure value of the hot air does not reach the hot gas pressure threshold, it means that the hot gas cannot be automatically transported from the air preheater 1 to the flue gas denitrification part 3 via the first pipeline 5. Therefore, it is necessary to open the second valve 9 on the second pipeline 6, and provide power for the hot air via the water-cooled fan 7 on the second pipeline 6, so that the hot air is transported from the air preheater 1 to the flue gas denitrification part 3.

[0044] In some embodiments, the number of the second valves 9 is one or more, wherein the second valves 9 can be sequentially connected or partially arranged on both sides of the water-cooling fan 7. Figure 2 As shown, there are two second valves 9, which are symmetrically arranged on both sides of the water-cooling fan 7, one of which is used to open or close the second pipeline 6 between the water-cooling fan 7 and the air preheater 1 based on a remote control signal, and the other second valve 9 is used to open or close the second pipeline 6 between the water-cooling fan 7 and the flue gas denitrification unit 3 based on a remote control signal. This arrangement on both sides of the water-cooling fan 7 can prevent the hot gas from diffusing to the second pipeline 6 when the hot gas is transported from the first pipeline 5, so that part of the hot gas is transported out through the second pipeline 6, which is conducive to improving the stability of the system.

[0045] In some embodiments, the water-cooling fan 7 is further configured to be in a closed state when the pressure value of the hot air reaches a preset value, and to be in an open state when the pressure value of the hot air does not reach the preset value. In one example, if the water-cooling fan 7 is abnormal, the second valve 9 is directly closed, and the abnormal water-cooling fan 7 is replaced by a spare water-cooling fan 7.

[0046] In some embodiments, the number of the first valve 8 is one or more. Figure 2 As shown, the number of the first valve 8 is one, and only one first valve 8 is provided on the passage pipe that is not connected to the water-cooled fan 7, so as to realize opening or closing of the first pipe 5 between the air preheater 1 and the flue gas denitrification part 3 based on a remote control signal.

[0047] In some embodiments, please refer to Figure 2 The flue gas denitrification section 3 includes an ammonia spraying pipeline 10 and an ammonia evaporator 11. The ammonia spraying pipeline 10 is used to input ammonia water; the ammonia evaporator 11 is connected to the air supply section 4 and the ammonia spraying pipeline 10. The ammonia evaporator 11 is used to evaporate the ammonia water into ammonia gas based on the hot air output from the air supply section 4 and output it.

[0048] In some embodiments, please refer to Figure 2 The flue gas denitration section 3 also includes an SCR reactor 12, which is connected to the ammonia evaporator 11. The SCR reactor 12 is used to react the ammonia output by the ammonia evaporator 11 with the flue gas to denitrate the flue gas. The ammonia evaporator 11 and the SCR reactor 12 are connected by a pipeline to form a continuous flue gas denitration process. The ammonia provided by the ammonia evaporator 11 acts as a reducing agent and reacts with nitrogen oxides in the flue gas in the SCR reactor 12 to jointly achieve the emission reduction target of nitrogen oxides in the flue gas, thereby ensuring the normal operation and high efficiency of the flue gas denitration system.

[0049] In some embodiments, the preset value is 1 kPa. In a specific example, during the process of boiler flue gas nitration, when the boiler hot air pressure value exceeds 1.0 kPa, the first valve 8 on the first pipe 5 is opened, and the second valve 9 on the second pipe 6 is closed (such as Figure 2 As shown, the second valve 9 includes an inlet valve and an outlet valve), the water-cooling fan 7 is turned off, and the hot air is transported to the ammonia evaporator 11 through the first pipeline 5, so that the hot air is directly supplied to the ammonia evaporator. When the pressure value of the hot air from the boiler does not exceed 1.0 kpa, the water-cooling fan 7 is started, the second valve 9 on the second pipeline 6 is opened, and the first valve 8 on the first pipeline 5 is closed, and the hot air is transported to the ammonia evaporator 11 through the water-cooling fan 7 to achieve ammonia evaporation. This not only ensures the safe, stable and economical operation of the flue gas denitrification system 100, but also reduces the operating time of the water-cooling fan 7 and reduces power consumption.

[0050] In order to further understand the flue gas denitrification system of the utility model, Figure 3 The schematic diagram of the structure of the flue gas denitrification system in the prior art is shown as follows: Figure 3 As shown, in the existing flue gas denitration system, the first pipe 13 includes a first valve 15, and the first pipe 13 is connected to the existing dilution fan 17, and the second pipe 14 includes a second valve 16, and the second pipe 14 is connected to the existing dilution fan 17. In the flue gas denitration system in the prior art, since the existing dilution fan has no water cooling function, it is very easy to be burned by hot air. During the flue gas denitration process, if the dilution fan 17 is burned by hot air, it cannot be known in time, and during the flue gas denitration process, both dilution fans 17 are online. If one of the dilution fans 17 fails, the dilution fan 17 cannot be replaced in time, which affects the safe and stable operation of the denitration system and reduces the denitration efficiency of the denitration system.

[0051] A flue gas denitrification system 100 of the utility model comprises an air preheater 1, a flue gas denitrification unit 3 and an air supply unit 4, wherein the air preheater 1 is used to heat the input air to obtain hot air and monitor the pressure value of the hot air, the flue gas denitrification unit 3 is used to denitrify the flue gas based on the hot air, the air supply unit 4 is connected to the air preheater 1 and the flue gas denitrification unit 3, the air supply unit 4 comprises a first pipeline 5 and a second pipeline 6, the second pipeline 6 comprises a water-cooled fan 7, the second pipeline 6 is used to transport the hot air passing through the water-cooled fan 7 to the flue gas denitrification unit 3 when the pressure value of the hot air does not reach a preset value, and the first pipeline 5 is used to directly transport the hot air to the flue gas denitrification unit 3 when the pressure value of the hot air reaches a preset value. In the above-mentioned flue gas denitrification system 100, a water-cooled fan 7 is used as a dilution fan, which can effectively reduce the risk of hot air burning the traditional dilution fan. At the same time, only one of the two channels of the air supply part 4 is connected to the water-cooled fan 7, that is, only one water-cooled fan 7 is online, and the other water-cooled fan 7 can be used as an offline standby water-cooled fan, and is adaptively transported to the flue gas denitrification part 3 through one of the channels according to the real-time pressure value of the hot air. This is beneficial to ensure the safe and stable operation of the flue gas denitrification system 100, reduce the consumption of the dilution fan by the flue gas consumption system 100, and help improve the air supply efficiency of the flue gas denitrification system 100, thereby improving the denitrification efficiency of the flue gas denitrification system 100.

[0052] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0053] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.

Claims

1. A flue gas denitrification system, characterized in that: include: An air preheater, the air preheater is used to heat the input air to obtain hot air, and the air preheater is provided with a pressure sensor for monitoring the pressure value of the hot air; A flue gas denitrification unit, used for denitrifying the flue gas based on the hot air; An air supply unit, the air supply unit is connected to the air preheater and the flue gas denitrification unit, and the air supply unit includes: a first pipeline, wherein the first pipeline is used to transport the hot air to the flue gas denitration part when the pressure value of the hot air reaches a preset value, The second pipeline includes a water-cooled fan, and the second pipeline is used to transport the hot air passing through the water-cooled fan to the flue gas denitrification part when the pressure value of the hot air does not reach the preset value.

2. The flue gas denitrification system according to claim 1, characterized in that: The first pipeline includes a first valve, and the first valve is used to be in an open state when the pressure value of the hot air reaches the preset value, and to be in a closed state when the pressure value of the hot air does not reach the preset value.

3. The flue gas denitrification system according to claim 2, characterized in that: The first valve is an electric valve.

4. The flue gas denitrification system according to claim 1, characterized in that: The second pipeline includes a second valve, the second valve is connected to the water-cooling fan, and the second valve is used to be in an open state when the pressure value of the hot air does not reach the preset value.

5. The flue gas denitrification system according to claim 4, characterized in that: The number of the second valves is one or more, and the multiple second valves are sequentially connected to the water-cooling fan or partially arranged on both sides of the water-cooling fan.

6. The flue gas denitrification system according to claim 1, characterized in that: The water-cooling fan is further configured to be in a closed state when the pressure value of the hot air reaches the preset value, and to be in an open state when the pressure value of the hot air does not reach the preset value.

7. The flue gas denitrification system according to claim 2, characterized in that: The number of the first valves is one or more.

8. The flue gas denitrification system according to claim 1, characterized in that: The flue gas denitrification unit comprises: Ammonia injection pipeline, used to input ammonia water; An ammonia evaporator is connected to the air supply unit and the ammonia injection pipeline, and is used to evaporate the ammonia water into ammonia gas based on the hot air output by the air supply unit and output the ammonia gas.

9. The flue gas denitrification system according to claim 8, characterized in that: The flue gas denitrification unit also includes: An SCR reactor is connected to the ammonia still, and is used to make the ammonia outputted by the ammonia still react with the flue gas to denitrate the flue gas.

10. The flue gas denitrification system according to claim 1, characterized in that: The preset value is 1 kPa.

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