System and method for adjusting flue gas temperature at inlet of SCR (Selective Catalytic Reduction) denitration device

Abstract

The invention discloses an SCR denitration device inlet flue gas temperature adjusting system and method, and the system comprises a denitration device which is provided with a flue gas inlet; the temperature control device comprises a water-cooling circulating box, a first pipeline, a first branch and a second branch, one end of the first pipeline is communicated with the outlet end of the dust removal device, the other end of the first pipeline is connected with one end of the first branch and one end of the second branch, the other end of the first branch is connected with the inlet end of the water-cooling circulating box, and the other end of the second branch is connected with the inlet end of the water-cooling circulating box; the outlet end of the water cooling circulation box communicates with the smoke inlet, and the other end of the second branch communicates with the main smoke exhaust pipeline. According to the SCR denitration device inlet smoke temperature adjusting system, the smoke entering the denitration device is cooled and heated through the smoke in the water cooling circulation box and the smoke in the main smoke exhaust pipeline, the temperature of the smoke entering the denitration device can be adjusted, and the SCR denitration device inlet smoke temperature adjusting system is simple in structure and low in production cost.

Description

Technical Field

[0001] The present invention relates to the technical field of boiler flue gas treatment, and in particular to a flue gas temperature regulation system and a regulation method at the inlet of an SCR denitration device. Background Art

[0002] Currently, SCR denitration devices are commonly used in boilers to reduce nitrogen oxides in boiler flue gas. During the operation of the SCR denitration device, the catalyst in the SCR denitration device requires the flue gas temperature to be within a specific range. The performance of the catalyst directly determines the denitration efficiency and stability of the flue gas denitration (SCR) system. The performance of the catalyst itself is closely related to the reaction temperature, and an appropriate reaction temperature is the key to optimizing the catalyst performance. When the flue gas temperature matches the optimal working temperature of the catalyst, the activity of the catalyst is maximized, thus ensuring the efficiency and completion rate of the denitration reaction. Improper temperature control will reduce the denitration efficiency, and may also exacerbate the aging and loss of the catalyst, shorten its service life, and increase the operating cost. The active centers of the catalyst are the key factors affecting its performance, and the activity intensity of these active centers changes with the temperature. Within a certain temperature range, an increase in temperature usually enhances the activity of the active centers, thereby improving the overall activity of the catalyst. When the temperature exceeds the optimal working temperature of the catalyst, the structure of the catalyst may undergo physical and chemical changes due to high temperature, such as lattice rearrangement, phase change, or microcrystalline sintering of the structure. These changes will cause the active centers of the catalyst to be irreversibly damaged or covered, thus reducing the activity of the catalyst. Improper temperature control may also accelerate the structural wear and the accumulation of thermal stress of the catalyst, which will further weaken the structural stability of the catalyst and lead to a rapid decline in its performance. In this case, the micropores and channels of the catalyst may undergo structural deformation, resulting in a reduction in the effective catalytic area, a decrease in the dispersion and transport efficiency of the reactants, and ultimately affecting the denitration reaction rate.

[0003] Therefore, during the design and operation of the SCR system, it is necessary to precisely control the flue gas temperature to ensure that the catalyst operates at its optimal working temperature. In order to maximize the denitration efficiency and the service life of the catalyst, strict control measures must be implemented for the flue gas temperature to ensure that the catalyst operates in the best working state. However, in the related art, the device structure for regulating the flue gas temperature at the inlet of the SCR denitration device is relatively complex and the production cost is high. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. For this reason, the present invention provides a flue gas temperature regulation system at the inlet of an SCR denitration device, and the flue gas temperature regulation system at the inlet of the SCR denitration device can regulate the flue gas temperature entering the denitration device and has a relatively simple structure.

[0005] The present invention also provides an adjustment method applied to the inlet flue gas temperature adjustment system of the above SCR denitration device.

[0006] The SCR denitration device inlet flue gas temperature adjustment system according to the first aspect of the present invention includes: a denitration device having a flue gas inlet; a furnace having a smoke exhaust port; a dust removal device and a main smoke exhaust pipeline, the inlet end of the dust removal device is connected to the smoke exhaust port through the main smoke exhaust pipeline; a temperature control device including: a water-cooled circulation tank, a first pipeline, a first branch and a second branch, one end of the first pipeline is connected to the outlet end of the dust removal device, the other end of the first pipeline is connected to one end of the first branch and one end of the second branch, the other end of the first branch is connected to the inlet end of the water-cooled circulation tank, the outlet end of the water-cooled circulation tank is connected to the flue gas inlet, the other end of the second branch is connected to the main smoke exhaust pipeline, a first temperature sensor is connected in series on the first pipeline, a second temperature sensor is provided in the water-cooled circulation tank, a first control valve is connected in series on the first branch, a second control valve is connected in series on the second branch, and a third control valve is connected in series between the outlet end of the water-cooled circulation tank and the flue gas inlet; a controller, the controller is electrically connected to the first temperature sensor, the second temperature sensor, the first control valve, the second control valve and the third control valve.

[0007] The SCR denitration device inlet flue gas temperature adjustment system according to the first aspect of the present invention can adjust the temperature of the flue gas entering the denitration device by cooling and heating the flue gas entering the denitration device with the flue gas in the water-cooled circulation tank and the main smoke exhaust pipeline respectively, and the structure of the SCR denitration device inlet flue gas temperature adjustment system is relatively simple and the production cost is relatively low.

[0008] According to some embodiments of the present invention, a first dust meter, a third temperature sensor and a pressure sensor are connected in series on the main smoke exhaust pipeline, and in the flue gas flow direction, the first dust meter, the third temperature sensor and the pressure sensor are arranged in sequence, and the first dust meter, the third temperature sensor and the pressure sensor are all electrically connected to the controller.

[0009] According to some embodiments of the present invention, the temperature control device further includes: a third branch and a fourth branch, the third branch and the fourth branch are connected in parallel between the outlet end of the dust removal device and the first pipeline, a fourth control valve is connected in series on the third branch, a pressure reducing valve is connected in series on the fourth branch, and the fourth control valve and the pressure reducing valve are both electrically connected to the controller.

[0010] According to some embodiments of the present invention, the dust removal device includes: a filter box and a main dust removal pipeline. One end of the main dust removal pipeline is connected to the main smoke exhaust pipeline, and the other end of the main dust removal pipeline forms the outlet end of the dust removal device. A second dust meter and a fifth control valve are connected in series in the main dust removal pipeline. The second dust meter is located between the pressure sensor and the fifth control valve. The inlet end of the filter box communicates with the main dust removal pipeline between the second dust meter and the fifth control valve, and the outlet end of the filter box communicates with the main dust removal pipeline between the fifth control valve and the temperature control device.

[0011] According to some embodiments of the present invention, the SCR denitration device inlet flue gas temperature regulation system further includes: a circulation pump, which is connected between the water-cooled circulation tank and the external water circuit to drive the water-cooled medium to circulate between the water-cooled circulation tank and the external water circuit.

[0012] According to some embodiments of the present invention, the denitration device has an exhaust port, and an exhaust valve is provided at the exhaust port.

[0013] According to the regulation method of the second aspect of the present invention, which is applied to the SCR denitration device inlet flue gas temperature regulation system according to the first aspect of the present invention, the regulation method includes: S1. The dust removal device processes the flue gas; S2. The flue gas enters the temperature control device; S3. Obtain the temperature T of the flue gas; S4. Judge the temperature T of the flue gas. If the first set temperature T1 ≤ T ≤ the second set temperature T2, enter step S5. If T > T2, control the flue gas to enter the water-cooled circulation tank, and the water-cooled circulation tank exchanges heat with the flue gas until the flue gas temperature is within the range of T1 - T2, then enter step S5. If T < T1, control the flue gas to enter the main smoke exhaust pipeline, and repeat steps S1 - S4; S5. The flue gas enters the denitration device.

[0014] According to the regulation method of the second aspect of the present invention, the SCR denitration device inlet flue gas temperature regulation system according to the first aspect of the present invention can regulate the inlet flue gas temperature of the denitration device, and the process is relatively simple.

[0015] According to some embodiments of the present invention, step S1 includes: S11. Obtain the dust concentration C in the flue gas; S12. Judge the dust concentration C. If C ≥ the set concentration C1, filter the flue gas, and the filtered flue gas enters the temperature control device. If C < the set concentration C1, the flue gas directly enters the temperature control device.

[0016] According to some embodiments of the present invention, before step S1, it further includes: S0. Obtain the pressure P, temperature T3, and dust concentration C2 of the flue gas in the main smoke exhaust pipeline.

[0017] According to some embodiments of the present invention, the temperature control device further includes: a third branch and a fourth branch. The third branch and the fourth branch are connected in parallel between the outlet end of the dust removal device and the first pipeline. A fourth control valve is connected in series on the third branch, and a pressure reducing valve is connected in series on the fourth branch. Between the step S2 and the step S3, the following is further included: S21. Determine the pressure P in the main exhaust pipeline. If P≥set pressure P1, control the pressure reducing valve to open and the fourth control valve to close. If P<set pressure P1, control the pressure reducing valve to close and the fourth control valve to open.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of an SCR denitration device inlet flue gas temperature regulation system according to an embodiment of the present invention;

[0020] Figure 2 is Figure 1 a schematic diagram of the dust removal device shown in

[0021] Figure 3 is Figure 1 a schematic diagram of the temperature control device shown in

[0022] Figure 4 is a flowchart of an adjustment method according to an embodiment of the present invention;

[0023] Figure 5 is Figure 4 a flowchart of step S1 shown in

[0024] Figure 6 is a flowchart of an adjustment method according to another embodiment of the present invention.

[0025] Reference Signs:

[0026] 100, SCR denitration device inlet flue gas temperature regulation system;

[0027] 10, denitration device; 11, flue gas inlet; 12, exhaust port; 121, exhaust valve;

[0028] 20, furnace; 21, smoke exhaust port;

[0029] 30, dust removal device; 31, filter box; 32, main dust removal pipeline; 321, second dust meter; 322, fifth control valve;

[0030] 40, main exhaust pipeline; 41, first dust meter; 42, third temperature sensor; 43, pressure sensor;

[0031] 50. Temperature control device; 51. Water-cooled circulation tank; 511. Circulation pump; 52. First pipeline; 521. First temperature sensor; 53. First branch; 531. First control valve; 54. Second branch; 541. Second control valve; 55. Third control valve; 56. Third branch; 561. Fourth control valve; 57. Fourth branch; 571. Pressure reducing valve. Detailed implementation manners

[0032] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals indicate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention and should not be construed as a limitation to the present invention.

[0033] Reference will be made below Figures 1-6 to describe the SCR denitration device inlet flue gas temperature regulation system 100 according to an embodiment of the first aspect of the present invention.

[0034] As Figures 1-4 shown, the SCR denitration device inlet flue gas temperature regulation system 100 according to an embodiment of the first aspect of the present invention includes: a denitration device 10, a furnace 20, a dust removal device 30, a main exhaust pipeline 40, a temperature control device 50, and a controller.

[0035] Specifically, the denitration device 10 has a flue gas inlet 11, the furnace 20 has an exhaust port 21, the inlet end of the dust removal device 30 is communicated with the exhaust port 21 through the main exhaust pipeline 40. The temperature control device 50 includes: a water-cooled circulation tank 51, a first pipeline 52, a first branch 53, and a second branch 54. One end of the first pipeline 52 is communicated with the outlet end of the dust removal device 30, the other end of the first pipeline 52 is connected to one end of the first branch 53 and one end of the second branch 54. The other end of the first branch 53 is connected to the inlet end of the water-cooled circulation tank 51, the outlet end of the water-cooled circulation tank 51 is communicated with the flue gas inlet 11, the other end of the second branch 54 is communicated with the main exhaust pipeline 40. A first temperature sensor 521 is connected in series on the first pipeline 52, a second temperature sensor is provided in the water-cooled circulation tank 51, a first control valve 531 is connected in series on the first branch 53, a second control valve 541 is connected in series on the second branch 54. A third control valve 55 is connected in series between the outlet end of the water-cooled circulation tank 51 and the flue gas inlet 11. The controller is electrically connected to the first temperature sensor 521, the second temperature sensor, the first control valve 531, the second control valve 541, and the third control valve 55.

[0036] Among them, the first pipeline 52 is connected to the first branch 53 and the second branch 54 through a three-way valve. The dust removal device 30 can process the flue gas according to the state of the flue gas. The water-cooled circulation tank 51 can exchange heat with the flue gas to cool the flue gas. The flue gas temperature range in which the denitration device 10 can efficiently denitrate is: the first set temperature T1 - the second set temperature T2, and the flue gas temperature in the main exhaust pipeline 40 is greater than the first set temperature T1.

[0037] In one example, T1 is 320 °C and T2 is 420 °C, that is, the flue gas temperature range in which the denitration device 10 can efficiently denitrate is: 320 °C - 420 °C, and the flue gas temperature in the main exhaust pipeline 40 is greater than 320 °C. For example, the flue gas temperature in the main exhaust pipeline 40 can be 320 °C, 370 °C, 389 °C, 420 °C or 430 °C.

[0038] In another example, T1 is 100 °C and T2 is 180 °C, that is, the flue gas temperature range in which the denitration device 10 can efficiently denitrate is: 100 °C - 180 °C, and the flue gas temperature in the main exhaust pipeline 40 is greater than 100 °C. For example, the flue gas temperature in the main exhaust pipeline 40 can be 100 °C, 120 °C, 150 °C, 180 °C or 190 °C.

[0039] During the operation of the inlet flue gas temperature regulation system 100 of the SCR denitration device, the flue gas in the furnace 20 enters the dust removal device 30 through the main exhaust pipeline 40 via the exhaust port 21. The dust removal device 30 processes the flue gas according to the state of the flue gas. Then the flue gas enters the first pipeline 52 from the dust removal device 30. The first temperature sensor 521 on the first pipeline 52 detects the flue gas temperature and transmits the detected flue gas temperature T to the controller. The controller determines the temperature T detected by the first temperature sensor 521 as follows:

[0040] If the first set temperature T1 ≤ T ≤ the second set temperature T2, it is determined that the flue gas temperature T is within the temperature range for efficient denitration of the denitration device 10. The controller controls the first control valve 531 and the third control valve 55 to open, and the second control valve 541 to close. The flue gas directly passes through the water-cooled circulation tank 51 and enters the flue gas inlet 11 of the denitration device 10.

[0041] If T > T2, it is determined that the flue gas temperature T is too high. The controller controls the first control valve 531 to open, the second control valve 541 and the third control valve 55 to close. The flue gas enters the water-cooled circulation tank 51 through the first branch 53 for cooling. At the same time, the second temperature sensor in the water-cooled circulation tank 51 detects the flue gas temperature therein and transmits the detected temperature data to the controller. The controller determines the temperature detected by the second temperature sensor. When the flue gas temperature in the water-cooled circulation tank 51 is within the range of T1 - T2, the controller controls the third control valve 55 to open, and the flue gas enters the flue gas inlet 11 of the denitration device 10.

[0042] If T < T1, it is determined that the flue gas temperature is too low, that is, the heat loss of the flue gas after passing through the dust removal device 30 is relatively high. The controller controls the first control valve 531 to close and the second control valve 541 to open. The flue gas returns to the main exhaust gas pipeline 40 through the second branch 54 and mixes with the flue gas in the main exhaust gas pipeline 40, thereby realizing the heating of the flue gas. Then the mixed flue gas enters the dust removal device 30 and repeats the above steps.

[0043] Thus, the flue gas temperature at the flue gas inlet 11 of the denitration device 10 can be adjusted, and the number of components of the SCR denitration device inlet flue gas temperature regulation system 100 is small, and the structure of the SCR denitration device inlet flue gas temperature regulation system 100 is relatively simple.

[0044] According to the SCR denitration device inlet flue gas temperature regulation system 100 of the first aspect embodiment of the present invention, the flue gas entering the denitration device 10 can be cooled and heated by the flue gas in the water-cooled circulation tank 51 and the main exhaust gas pipeline 40 respectively, so that the flue gas temperature entering the denitration device 10 can be adjusted, and the structure of the SCR denitration device inlet flue gas temperature regulation system 100 is relatively simple and the production cost is low.

[0045] In some embodiments of the present invention, as Figure 1 shown, a first dust meter 41, a third temperature sensor 42 and a pressure sensor 43 are connected in series to the main exhaust gas pipeline 40, and in the flue gas flow direction, the first dust meter 41, the third temperature sensor 42 and the pressure sensor 43 are arranged in sequence. The first dust meter 41, the third temperature sensor 42 and the pressure sensor 43 are all electrically connected to the controller.

[0046] Thus, the first dust meter 41 can detect the dust concentration in the flue gas flowing out of the furnace 20, the third temperature sensor 42 can detect the flue gas temperature flowing out of the furnace 20, and the pressure sensor 43 can detect the air pressure in the main exhaust gas pipeline. In this way, during the operation of the furnace 20, the working state in the furnace 20 can be monitored and adjusted according to the above detected data, which helps to improve the combustion state in the furnace 20.

[0047] In some embodiments of the present invention, as Figure 3 shown, the temperature control device 50 further includes: a third branch 56 and a fourth branch 57. The third branch 56 and the fourth branch 57 are connected in parallel between the outlet end of the dust removal device 30 and the first pipeline 52. A fourth control valve 561 is connected in series on the third branch 56, and a pressure reducing valve 571 is connected in series on the fourth branch 57. Both the fourth control valve 561 and the pressure reducing valve 571 are electrically connected to the controller.

[0048] Among them, the outlet end of the dust removal device 30 is connected to the third branch 56 and the third branch 56 through a three-way valve.

[0049] During the operation of the SCR denitration device inlet flue gas temperature regulation system 100, as Figure 6 shown, the controller determines the pressure P detected by the pressure sensor 43 on the main exhaust pipeline 40 as follows:

[0050] If P ≥ the set pressure P1, it is determined that the pressure of the flue gas is greater than the normal operating pressure range of the subsequent components. The controller controls the pressure reducing valve 571 to open and the fourth control valve 561 to close. The flue gas enters the first pipeline 52 through the fourth branch 57. During the process of the flue gas passing through the pressure reducing valve 571, the pressure reducing valve 571 can reduce the pressure of the flue gas below P1. In this way, the pressure of the flue gas can be within the normal operating pressure range of the subsequent components.

[0051] If P < the set pressure P1, it is determined that the pressure of the flue gas is within the normal operating pressure range of the subsequent components. The controller controls the pressure reducing valve 571 to close and the fourth control valve 561 to open. The flue gas enters the first pipeline 52 through the third branch 56. During the process of the flue gas passing through the fourth control valve 561, the fourth control valve 561 does not change the pressure of the flue gas. Among them, in different types of boiler systems, the set pressure P1 is also different. For example, the set pressure P1 can be 350 Pa.

[0052] Thus, the flue gas can be diverted according to the air pressure in the main exhaust pipeline 40, making the pressure of the flue gas input into the denitration device 10 more stable, thereby improving the reliability during the operation of the SCR denitration device inlet flue gas temperature regulation system 100.

[0053] In some embodiments of the present invention, as Figure 2As shown in the figure, the dust removal device 30 includes a filter box 31 and a main dust removal pipeline 32. One end of the main dust removal pipeline 32 is connected to the main flue gas pipeline 40, and the other end of the main dust removal pipeline 32 forms the outlet end of the dust removal device 30. The main dust removal pipeline 32 is connected in series with a second dust meter 321 and a fifth control valve 322. The second dust meter 321 is located between the pressure sensor 43 and the fifth control valve 322. The inlet end of the filter box 31 is communicated with the main dust removal pipeline 32 between the second dust meter 321 and the fifth control valve 322, and the outlet end of the filter box 31 is communicated with the main dust removal pipeline 32 between the fifth control valve 322 and the temperature control device 50.

[0054] After the flue gas enters the main dust removal pipeline 32, as Figure 5 shown, the second dust meter 321 detects the dust concentration in the flue gas again, and transmits the detected dust concentration C to the controller. The controller determines the dust concentration C as follows:

[0055] If C ≥ the set concentration C1, it is determined that the dust concentration is too high and it is easy to block the subsequent flow path. The controller controls the fifth control valve 322 to close, and the flue gas passes through the filter box 31 and then returns to the main dust removal pipeline 32. Thus, the filtration of the flue gas is realized, and the probability of the flue gas blocking the subsequent flow path and components can be reduced.

[0056] If C < the set concentration C1, it is determined that the probability of the dust concentration blocking the subsequent flow path is relatively low, and the flue gas directly enters the temperature control device 50 for subsequent steps.

[0057] Thus, it is possible to select whether to filter the dust according to the dust concentration in the flue gas. Compared with continuously filtering the flue gas, the probability of the flue gas passing through the dust removal device 30 can be increased, thereby improving the denitration efficiency of the flue gas.

[0058] Among them, in different SCR denitration device inlet flue gas temperature adjustment systems 100, the flow path of the flue gas and the size parameters of each component are different, and the set concentration C1 is also different. During the product design process, the set concentration C1 can be adjusted according to the flow path of the flue gas and the size parameters of each component.

[0059] In some embodiments of the present invention, as Figure 1 shown, the SCR denitration device inlet flue gas temperature adjustment system 100 further includes a circulation pump 511. The circulation pump 511 is connected between the water cooling circulation tank 51 and the external water circuit to drive the water cooling medium to circulate between the water cooling circulation tank 51 and the external water circuit.

[0060] During the operation of the inlet flue gas temperature regulation system 100 of the SCR denitration device, the circulation pump 511 drives the water-cooled medium to circulate between the water-cooled circulation tank 51 and the external water circuit. In this way, during the flow of the water-cooled medium, it can continuously exchange heat with the flue gas in the water-cooled circulation tank 51, thereby realizing the cooling of the flue gas by the water-cooled circulation tank 51.

[0061] In some embodiments of the present invention, as Figure 1 shown, the denitration device 10 has an exhaust port 12, and an exhaust valve 121 is provided at the exhaust port 12.

[0062] During the operation of the denitration device 10, when it is necessary to exhaust the denitration device 10, the exhaust valve 121 is opened to exhaust the denitration device 10. When the denitration device 10 denitrates the flue gas, the exhaust valve 121 is closed to make the denitration device 10 in a closed state. Thus, the control during the exhaust process of the denitration device 10 can be realized.

[0063] Next, refer to Figures 1-6 to describe the regulation method according to the second aspect embodiment of the present invention.

[0064] The regulation method according to the second aspect embodiment of the present invention is applied to the SCR denitration device inlet flue gas temperature regulation system 100 according to the first aspect embodiment of the present invention, as Figure 4 shown, the regulation method includes:

[0065] S1. The dust removal device 30 processes the flue gas.

[0066] The flue gas in the furnace 20 enters the dust removal device 30 through the main exhaust pipeline 40, and the dust removal device 30 processes the flue gas according to the state of the flue gas.

[0067] S2. The flue gas enters the temperature control device 50.

[0068] The flue gas processed by the dust removal device 30 enters the first pipeline 52 of the temperature control device 50.

[0069] S3. Obtain the temperature T of the flue gas.

[0070] The first temperature sensor 521 on the first pipeline 52 detects the flue gas temperature to obtain the temperature T, and transmits the temperature T to the controller.

[0071] S4. Judge the temperature T of the flue gas,

[0072] If the first set temperature T1 ≤ T ≤ the second set temperature T2, enter step S5,

[0073] If T > T2, then control the flue gas to enter the water-cooled circulation tank 51, and the water-cooled circulation tank 51 exchanges heat with the flue gas until the flue gas temperature is within the range of T1 - T2, and then enter step S5.

[0074] If T < T1, control the flue gas to enter the main exhaust pipe 40, and repeat steps S1 - S4;

[0075] S5. The flue gas enters the denitration device 10.

[0076] Among them, the flue gas temperature range in which the denitration device 10 can efficiently denitrate is: the first set temperature T1 - the second set temperature T2, and the flue gas temperature in the main exhaust pipe 40 is greater than the first set temperature T1.

[0077] In one example, T1 is 320 °C and T2 is 420 °C, that is, the flue gas temperature range in which the denitration device 10 can efficiently denitrate is: 320 °C - 420 °C, and the flue gas temperature in the main exhaust pipe 40 is greater than 320 °C. For example, the flue gas temperature in the main exhaust pipe 40 can be 320 °C, 370 °C, 389 °C, 420 °C or 430 °C.

[0078] In another example, T1 is 100 °C and T2 is 180 °C, that is, the flue gas temperature range in which the denitration device 10 can efficiently denitrate is: 100 °C - 180 °C, and the flue gas temperature in the main exhaust pipe 40 is greater than 100 °C. For example, the flue gas temperature in the main exhaust pipe 40 can be 100 °C, 120 °C, 150 °C, 180 °C or 190 °C.

[0079] When T1 ≤ T ≤ T2, the flue gas temperature T is within the efficient denitration temperature range of the denitration device 10, and the flue gas directly enters the denitration device 10 for denitration.

[0080] When T > T2, the flue gas temperature T is too high and the flue gas needs to be cooled. At this time, control the flue gas to enter the water-cooled circulation tank 51, and the water-cooled circulation tank 51 cools the flue gas. When the flue gas temperature is in the range of T1 - T2, the flue gas enters the denitration device 10 from the water-cooled circulation tank 51 for denitration.

[0081] When T < T1, the flue gas temperature T is relatively low and the flue gas needs to be heated. At this time, control the flue gas to enter the main exhaust pipe 40, and the flue gas mixes with the flue gas in the main exhaust pipe 40. In this way, the temperature of the mixed flue gas is relatively high, and then repeat the above steps.

[0082] According to the adjustment method of the second aspect embodiment of the present invention, the adjustment of the inlet flue gas temperature of the denitration device 10 by the SCR denitration device inlet flue gas temperature adjustment system 100 according to the first aspect of the present invention can be realized, and the process is relatively simple.

[0083] In some embodiments of the present invention, as Figure 5 shown, step S1 includes:

[0084] S11. Obtain the dust concentration C in the flue gas;

[0085] S12. Determine the dust concentration C.

[0086] If C ≥ the set concentration C1, then filter the flue gas, and the filtered flue gas enters the temperature control device 50.

[0087] If C < the set concentration C1, then the flue gas directly enters the temperature control device 50.

[0088] Among them, when C ≥ the set concentration C1, it is determined that the dust concentration is too high and it is easy to block the subsequent flow path. The controller controls the dust removal device 30 to filter the flue gas, reducing the probability of the flue gas blocking the subsequent flow path and components.

[0089] When C < the set concentration C1, it is determined that the probability of the dust concentration blocking the subsequent flow path is relatively low. The controller controls the flue gas to directly enter the dust removal device 30. In this way, the passing efficiency of the flue gas can be improved, thereby improving the denitration efficiency.

[0090] In different SCR denitration device inlet flue gas temperature adjustment systems 100, the flow path of the flue gas and the size parameters of each component are different, and the set concentration C1 is also different. During the product design process, the set concentration C1 can be adjusted according to the flow path of the flue gas and the size parameters of each component.

[0091] In some embodiments of the present invention, as Figure 6 shown, before step S1, it further includes:

[0092] S0. Obtain the pressure P, temperature T3, and dust concentration C2 of the flue gas in the main exhaust pipe 40.

[0093] In this way, during the operation of the furnace 20, the working state in the furnace 20 can be monitored and adjusted according to the above detected data, which helps to improve the combustion state in the furnace 20.

[0094] In some embodiments of the present invention, as Figure 6 shown, the temperature control device 50 further includes: a third branch 56 and a fourth branch 57. The third branch 56 and the fourth branch 57 are connected in parallel between the outlet end of the dust removal device 30 and the first pipeline 52. A fourth control valve 561 is connected in series on the third branch 56, and a pressure reducing valve 571 is connected in series on the fourth branch 57. Before step S2 and step S3, it further includes:

[0095] S21. Determine the pressure P in the main exhaust pipe 40.

[0096] If P ≥ the set pressure P1, then control the pressure reducing valve 571 to open and the fourth control valve 561 to close.

[0097] If P < set pressure P1, control the pressure reducing valve 571 to close and the fourth control valve 561 to open.

[0098] Among them, when P ≥ set pressure P1, it is determined that the pressure of the flue gas is greater than the normal operating pressure range of the subsequent components. The flue gas enters the first pipeline 52 through the fourth branch 57. During the process of the flue gas passing through the pressure reducing valve 571, the pressure reducing valve 571 can reduce the pressure of the flue gas below P1. In this way, the pressure of the flue gas can be within the normal operating pressure range of the subsequent components.

[0099] When P < set pressure P1, it is determined that the pressure of the flue gas is within the normal operating pressure range of the subsequent components. The flue gas enters the first pipeline 52 through the third branch 56. During the process of the flue gas passing through the fourth control valve 561, the fourth control valve 561 does not change the pressure of the flue gas. Among them, in different types of boiler systems, the set pressure P1 is also different. For example, the set pressure P1 can be 350 Pa.

[0100] Thus, the flue gas can be shunted according to the air pressure in the main exhaust pipeline 40, making the pressure of the flue gas input into the denitration device 10 more stable, thereby improving the reliability during the operation of the SCR denitration device inlet flue gas temperature regulation system 100.

[0101] The following describes a specific embodiment of the SCR denitration device inlet flue gas temperature regulation system according to the present invention applying the regulation method according to the present invention.

[0102] The SCR denitration device inlet flue gas temperature regulation system includes: a denitration device 10, a furnace 20, a dust removal device 30, a main exhaust pipeline 40, a temperature control device 50, and a controller.

[0103] Specifically, the denitration device 10 has a flue gas inlet 11 and an exhaust port 12. An exhaust valve 121 is provided at the exhaust port 12. The furnace 20 has a smoke exhaust port 21. The inlet end of the dust removal device 30 is connected to the smoke exhaust port 21 through the main exhaust pipeline 40. In the flue gas flow direction, the main exhaust pipeline 40 is connected in series with a first dust meter 41, a third temperature sensor 42, and a pressure sensor 43.

[0104] The dust removal device 30 includes: a filter box 31 and a main dust removal pipeline 32. One end of the main dust removal pipeline 32 is connected to the main exhaust pipeline 40, and the other end of the main dust removal pipeline 32 forms the outlet end of the dust removal device 30. The main dust removal pipeline 32 is connected in series with a second dust meter 321 and a fifth control valve 322. The second dust meter 321 is located between the pressure sensor 43 and the fifth control valve 322. The inlet end of the filter box 31 is connected to the main dust removal pipeline 32 between the second dust meter 321 and the fifth control valve 322, and the outlet end of the filter box 31 is connected to the main dust removal pipeline 32 between the fifth control valve 322 and the temperature control device 50.

[0105] The temperature control device 50 includes: a water-cooling circulation tank 51, a first pipeline 52, a first branch 53, a second branch 54, a third branch 56, a fourth branch 57, and a circulation pump 511. The circulation pump 511 is connected between the water-cooling circulation tank 51 and the external water circuit to drive the water-cooling medium to circulate between the water-cooling circulation tank 51 and the external water circuit.

[0106] The third branch 56 and the fourth branch 57 are connected in parallel between the outlet end of the dust removal device 30 and the first pipeline 52. A fourth control valve 561 is connected in series on the third branch 56, and a pressure reducing valve 571 is connected in series on the fourth branch 57. The other end of the first pipeline 52 is connected to one end of the first branch 53 and one end of the second branch 54. The other end of the first branch 53 is connected to the inlet end of the water-cooling circulation tank 51. The outlet end of the water-cooling circulation tank 51 is communicated with the flue gas inlet 11. The other end of the second branch 54 is communicated with the main exhaust pipeline. A first temperature sensor 521 is connected in series on the first pipeline 52. A second temperature sensor is provided in the water-cooling circulation tank 51. A first control valve 531 is connected in series on the first branch 53. A second control valve 541 is connected in series on the second branch 54. A third control valve 55 is connected in series between the outlet end of the water-cooling circulation tank 51 and the flue gas inlet 11.

[0107] The controller is electrically connected to the first dust meter 41, the third temperature sensor 42, the pressure sensor 43, the second dust meter 321, the fifth control valve 322, the fourth control valve 561, the pressure reducing valve 571, the first temperature sensor 521, the second temperature sensor, the first control valve 531, the second control valve 541, and the third control valve 55.

[0108] The working process of the SCR denitration device inlet flue gas temperature regulation system 100 is described below.

[0109] During the working process of the SCR denitration device inlet flue gas temperature regulation system 100, the flue gas in the furnace 20 enters the dust removal main pipeline 32 through the smoke exhaust port 21 and the main exhaust pipeline 40. During the flow of the flue gas in the main exhaust pipeline 40, the first dust meter 41, the third temperature sensor 42, and the pressure sensor 43 sequentially detect the pressure P, temperature T3, and dust concentration C2 of the flue gas.

[0110] The second dust meter 321 detects the flue gas entering the dust removal main pipeline 32 and transmits the detected dust concentration C to the controller. The controller determines the dust concentration C as follows:

[0111] If C ≥ the set concentration C1, it is determined that the dust concentration is too high and it is easy to block the subsequent flow path. The controller controls the fifth control valve 322 to close. The flue gas passes through the filter box 31 and then returns to the dust removal main pipeline 32, and then flows out from the dust removal main pipeline 32.

[0112] If C < set concentration C1, it is determined that the probability of dust concentration blocking the subsequent flow path is low, and the flue gas directly flows out along the main dust removal pipeline 32.

[0113] The controller determines the pressure P of the flue gas. If P ≥ set pressure P1, it is determined that the pressure of the flue gas is greater than the normal operating pressure range of the subsequent components. The controller controls the pressure reducing valve 571 to open and the fourth control valve 561 to close. The flue gas flowing out of the main dust removal pipeline 32 enters the first pipeline 52 through the fourth branch 57. During the process of the flue gas passing through the pressure reducing valve 571, the pressure reducing valve 571 can reduce the pressure of the flue gas to below P1.

[0114] If P < set pressure P1, it is determined that the pressure of the flue gas is within the normal operating pressure range of the subsequent components. The controller controls the pressure reducing valve 571 to close and the fourth control valve 561 to open. The flue gas flowing out of the main dust removal pipeline 32 enters the first pipeline 52 through the third branch 56. During the process of the flue gas passing through the fourth control valve 561, the fourth control valve 561 does not change the pressure of the flue gas.

[0115] The first temperature sensor 521 on the first pipeline 52 detects the temperature of the flue gas and transmits the detected flue gas temperature T to the controller. The controller determines the temperature T detected by the first temperature sensor 521 as follows:

[0116] If the first set temperature T1 ≤ T ≤ the second set temperature T2, it is determined that the flue gas temperature T is within the temperature range for efficient denitrification of the denitrification device 10. The controller controls the first control valve 531 and the third control valve 55 to open and the second control valve 541 to close. The flue gas directly passes through the water cooling circulation tank 51 and enters the flue gas inlet 11 of the denitrification device 10.

[0117] If T > T2, it is determined that the flue gas temperature T is too high. The controller controls the first control valve 531 to open and the second control valve 541 and the third control valve 55 to close. The flue gas enters the water cooling circulation tank 51 through the first branch 53 for cooling. At the same time, the second temperature sensor in the water cooling circulation tank 51 detects the temperature of the flue gas therein and transmits the detected temperature data to the controller. The controller determines the temperature detected by the second temperature sensor. When the flue gas temperature in the water cooling circulation tank 51 is within the range of T1 - T2, the controller controls the third control valve 55 to open and the flue gas enters the flue gas inlet 11 of the denitrification device 10.

[0118] If T < T1, it is determined that the flue gas temperature is too low, that is, the heat loss of the flue gas after passing through the dust removal device 30 is relatively high. The controller controls the first control valve 531 to close and the second control valve 541 to open. The flue gas returns to the main exhaust pipeline 40 through the second branch 54 and mixes with the flue gas in the main exhaust pipeline 40, thereby realizing the heating of the flue gas. Then the mixed flue gas enters the dust removal device 30 and repeats the above steps.

[0119] After the flue gas enters the denitration device 10, the denitration device 10 denitrates the flue gas. After the denitration is completed, the exhaust valve 121 is opened to exhaust the denitration device 10.

[0120] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0121] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0122] In the present invention, unless otherwise clearly specified and defined, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or a communication; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0123] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0124] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. An inlet flue gas temperature regulation system for an SCR denitration device, characterized in that, Comprising: A denitration device having a flue gas inlet; A furnace having a smoke exhaust port; A dust removal device and a main smoke exhaust pipeline, the inlet end of the dust removal device being communicated with the smoke exhaust port through the main smoke exhaust pipeline; A temperature control device, the temperature control device comprising: a water-cooled circulation tank, a first pipeline, a first branch and a second branch, one end of the first pipeline being communicated with the outlet end of the dust removal device, the other end of the first pipeline being connected to one end of the first branch and one end of the second branch, the other end of the first branch being connected to the inlet end of the water-cooled circulation tank, the outlet end of the water-cooled circulation tank being communicated with the flue gas inlet, and the other end of the second branch being communicated with the main smoke exhaust pipeline; A first temperature sensor is connected in series on the first pipeline, a second temperature sensor is arranged in the water-cooled circulation tank, a first control valve is connected in series on the first branch, a second control valve is connected in series on the second branch, and a third control valve is connected in series between the outlet end of the water-cooled circulation tank and the flue gas inlet; A controller, the controller being electrically connected to the first temperature sensor, the second temperature sensor, the first control valve, the second control valve and the third control valve.

2. The SCR denitration device inlet flue gas temperature regulation system according to claim 1, characterized in that The main smoke exhaust pipeline is connected in series with a first dust meter, a third temperature sensor and a pressure sensor, and in the flue gas flow direction, the first dust meter, the third temperature sensor and the pressure sensor are arranged in sequence, and the first dust meter, the third temperature sensor and the pressure sensor are all electrically connected to the controller.

3. The SCR denitration device inlet flue gas temperature regulation system according to claim 2, characterized in that The temperature control device further comprises: a third branch and a fourth branch, the third branch and the fourth branch being connected in parallel between the outlet end of the dust removal device and the first pipeline, a fourth control valve being connected in series on the third branch, a pressure reducing valve being connected in series on the fourth branch, and the fourth control valve and the pressure reducing valve being both electrically connected to the controller.

4. The SCR denitration device inlet flue gas temperature regulation system according to claim 2, wherein The dust removal device comprises: a filter box and a main dust removal pipeline, one end of the main dust removal pipeline being connected to the main smoke exhaust pipeline, the other end of the main dust removal pipeline forming the outlet end of the dust removal device, the main dust removal pipeline being connected in series with a second dust meter and a fifth control valve, the second dust meter being located between the pressure sensor and the fifth control valve; The inlet end of the filter box is communicated with the main dust removal pipeline between the second dust meter and the fifth control valve, and the outlet end of the filter box is communicated with the main dust removal pipeline between the fifth control valve and the temperature control device.

5. The SCR denitration device inlet flue gas temperature regulation system according to claim 1, characterized in that, The SCR denitration device inlet flue gas temperature regulation system further comprises: a circulation pump, the circulation pump being connected between the water-cooled circulation tank and an external water circuit to drive the water-cooled medium to circulate between the water-cooled circulation tank and the external water circuit.

6. The SCR denitration device inlet flue gas temperature regulation system according to claim 1, characterized in that, The denitration device has an exhaust port, and an exhaust valve is provided at the exhaust port.

7. A regulation method, characterized in that Applied to the SCR denitration device inlet flue gas temperature regulation system according to any one of claims 1-6, the regulation method comprises: S1. The dust removal device processes the flue gas; S2. The flue gas enters the temperature control device; S3. Obtain the temperature T of the flue gas; S4. Judge the temperature T of the flue gas. If the first set temperature T1 ≤ T ≤ the second set temperature T2, enter step S5. If T > T2, control the flue gas to enter the water-cooled circulation tank. The water-cooled circulation tank exchanges heat with the flue gas until the flue gas temperature is within the range of T1 - T2, and then enter step S5. If T < T1, control the flue gas to enter the main exhaust pipe, and repeat steps S1 - S4. S5. The flue gas enters the denitration device.

8. The adjustment method according to claim 7, characterized in that, The said step S1 includes: S11. Obtain the dust concentration C in the flue gas. S12. Judge the dust concentration C. If C ≥ the set concentration C1, filter the flue gas, and the filtered flue gas enters the temperature control device. If C < the set concentration C1, the flue gas directly enters the temperature control device.

9. The adjustment method according to claim 7, characterized in that Before the said step S1, it also includes: S0. Obtain the pressure P, temperature T3 and dust concentration C2 of the flue gas in the main exhaust pipe.

10. The adjustment method according to claim 9, wherein the temperature control device further comprises: The third branch and the fourth branch. The third branch and the fourth branch are connected in parallel between the outlet end of the dust removal device and the first pipeline. A fourth control valve is connected in series on the third branch, and a pressure reducing valve is connected in series on the fourth branch. It is characterized in that, between the said step S2 and the said step S3, it also includes: S21. Judge the pressure P in the main exhaust pipe. If P ≥ the set pressure P1, control the pressure reducing valve to open and the fourth control valve to close. If P < the set pressure P1, control the pressure reducing valve to close and the fourth control valve to open.

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