SCR differential pressure optimization control method based on program-controlled soot blower

Abstract

The invention discloses an SCR differential pressure optimization control method based on a program-controlled soot blower, and relates to the technical field of differential pressure control, in particular to the SCR differential pressure optimization control method based on the program-controlled soot blower. Comprising the steps that a PLC improves a soot blower loop and processes data, the soot blowing time and the soot blowing stroke are dynamically adjusted, the PLC controls logic to adjust soot blowing parameters, the soot blower and the load working condition are automatically matched, and the soot blowing time stroke is increased to clean the SCR. According to the method, the soot blowing time and stroke of the soot blower are dynamically adjusted by monitoring the SCR differential pressure and the load working condition of the generator set in real time, and the problem that the SCR differential pressure is too high is effectively solved. In addition, full-automatic adjustment is achieved through a programmable controller, the intelligent level and the automation level of the system are improved, the equipment operation efficiency is improved, and energy consumption and equipment abrasion are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of pressure difference control, in particular to an SCR pressure difference optimization control method based on a program-controlled soot blower. Background Art

[0002] Coal-fired boilers are equipped with SCR denitration systems. To ensure the cleanliness of the catalyst, the catalyst is usually equipped with a rake soot blower. The soot blower operates in a continuous manner, and then exits continuously after entering the position. When the boiler burns high-ash and high-alkalinity coal, it will cause the SCR catalyst to be blocked, resulting in high SCR differential pressure, ammonia escape from the denitration system, and limited load capacity of the unit. The existing soot blower control system has the following disadvantages: Since the distribution and accumulation rate of ash accumulation inside the SCR vary with changes in load conditions, fixed sootblowing strategies cannot adapt to such dynamic changes, resulting in incomplete removal of ash accumulation in some areas or excessive sootblowing in other areas, making it impossible to achieve targeted soot cleaning. Traditional systems lack the ability to dynamically adjust sootblowing time and stroke based on real-time differential pressure and load data, resulting in the inability to increase sootblowing intensity in time when the differential pressure is too high, and continued excessive sootblowing when the differential pressure returns to normal, which not only wastes energy but also fails to effectively reduce the differential pressure. Therefore, the existing control system cannot effectively solve the problem of excessively high SCR differential pressure, which in turn affects the stable operation and economy of the unit. Summary of the invention

[0003] The main purpose of the present invention is to provide an SCR differential pressure optimization control method based on a programmable sootblower, which can effectively solve the problems in the background technology.

[0004] To achieve the above object, the technical solution adopted by the present invention is: PLC improves sootblower circuit and data processing, dynamically adjusts sootblowing time and sootblowing stroke, PLC control logic adjusts sootblowing parameters, automatically matches sootblower and load conditions, and increases sootblowing time and stroke to clean SCR; Step S1: Use a programmable controller to improve the loop.

[0005] Step S2: adjusting the sootblowing time and sootblowing stroke of the sootblower according to the real-time differential pressure data of the SCR and the load condition of the generator set.

[0006] Step S3: The PLC control logic adjusts the sootblowing time and sootblowing stroke parameters of the sootblower according to the real-time load and differential pressure changes.

[0007] Step S4: Automatically adjust the soot blowing time and soot blowing stroke according to the change of the generator set load.

[0008] Step S5: When the SCR differential pressure is too high, increase the soot blowing time or soot blowing stroke.

[0009] Furthermore, in step S1, the programmed controller improves the traditional sootblower circuit by connecting the sootblower, receiving SCR differential pressure data and generator set load data, and performing data processing.

[0010] Furthermore, in step S2, the sootblowing time and sootblowing stroke of the sootblower are dynamically adjusted according to the real-time differential pressure data of the SCR and the load condition of the generator set. If the differential pressure data is slightly abnormal, normal sootblowing is adopted, with continuous advance and retreat; if the differential pressure data is abnormal, short-time fixed-point sootblowing is adopted; if the differential pressure data is seriously abnormal, long-time fixed-point sootblowing is adopted.

[0011] Furthermore, in step S3, the PLC control logic adjusts the control time and stroke parameters of the soot blower according to the load conditions and SCR differential pressure changes monitored in real time to reduce the differential pressure.

[0012] Furthermore, in step S4, the method automatically adjusts the sootblowing time and stroke of the sootblower through PLC, and the working state is matched with the load condition of the generator set in real time.

[0013] Further, in step S5, when the SCR differential pressure exceeds a preset threshold, the PLC enhances the sootblowing effect of the sootblower by increasing the sootblowing time or stroke.

[0014] Further, the PLC controls the soot blower by executing the G00 group logic, which includes the following steps: Close the sootblower control output (Q02).

[0015] Delay N seconds to control the stroke of the soot blower.

[0016] Disconnect the sootblower control output (Q02).

[0017] Delay M seconds to control the sootblower's sootblowing time on the stroke.

[0018] Furthermore, the delay parameters N and M are dynamically adjusted by the PLC according to the real-time differential pressure data of the SCR and the load condition of the generator set.

[0019] Furthermore, the logic is triggered by conditional judgment, and when the SCR differential pressure exceeds a preset threshold, the G00 group logic is automatically executed to clean the SCR.

[0020] Compared with the prior art, the present invention has the following beneficial effects: In order to adapt to the burning of high-ash and high-alkalinity coal, the soot blower advance, stop and retreat logic is set through PLC. Flexible adjustment of the soot blower operation mode is achieved. After adjustment, the soot blower is started, and the PLC randomly generates a first advance time of 10 to 30 seconds. When the first advance time is up, the soot blower stops and keeps blowing soot at the fixed position. When the set soot blowing time is up, the soot blower advances again. When the advance time is up, the soot blower stops and keeps blowing soot at the fixed position. This cycle is repeated in sequence until it enters the right position, and the soot blower exits after entering the right position.

[0021] The present invention uses a dynamic control method based on PLC to accurately adjust the sootblowing time and stroke of the sootblower, effectively solving the problem that the existing sootblowing system cannot effectively suppress the excessively high SCR differential pressure. By real-time monitoring of the differential pressure of the SCR and the load condition of the generator set, the system can automatically adjust the sootblowing parameters according to different operating conditions to ensure that the SCR is fully cleaned under different load and differential pressure conditions, avoiding the energy waste and incomplete cleaning problems caused by fixed-cycle sootblowing in traditional methods. When the SCR has a high differential pressure due to blockage, the system can ensure that the accumulated ash is completely removed and the differential pressure is reduced by increasing the sootblowing time and stroke, thereby maintaining the optimal operating state of the SCR and reducing unit shutdown or load reduction caused by differential pressure problems.

[0022] The control method of the present invention improves the intelligence and automation level of the system and reduces the need for manual intervention. Through real-time adjustment of the PLC controller, the system can accurately adjust the operation of the soot blower under different load conditions, which not only optimizes the soot blowing process and saves energy, but also extends the service life of the equipment and reduces the operation and maintenance costs. The flexibility and adaptability of the method greatly improve the stability and economy of the unit, ensure that the SCR differential pressure is always within the optimal range, and significantly improve the economic benefits of the power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a power distribution diagram of the sootblower power cabinet of the present invention; Figure 3 This is the control principle diagram of the sootblower power cabinet of the present invention. DETAILED DESCRIPTION

[0024] The subject matter described herein will now be discussed with reference to example embodiments. It should be understood that the discussion of these embodiments is only to enable those skilled in the art to better understand and implement the subject matter described herein, and is not a limitation of the scope of protection, applicability or examples set forth in the claims. The functions and arrangements of the elements discussed can be changed without departing from the scope of protection of the contents of this specification. Various examples can omit, replace or add various processes or components as needed. For example, the described method can be performed in an order different from the described order, and various steps can be added, omitted or combined. In addition, the features described relative to some examples can also be combined in other examples.

[0025] As used herein, the term "including" and its variations represent open terms, meaning "including but not limited to". The term "based on" means "based at least in part on". The terms "one embodiment" and "an embodiment" mean "at least one embodiment". The term "another embodiment" means "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other definitions may be included below, whether explicit or implicit. Unless the context clearly indicates otherwise, the definition of a term is consistent throughout the specification.

[0026] Example See also Figure 1-3 , the present invention provides a technical solution: A SCR differential pressure optimization control method based on program-controlled sootblower. PLC improves the sootblower circuit and data processing, dynamically adjusts the sootblowing time and sootblowing stroke, uses PLC control logic to adjust sootblowing parameters, automatically matches the sootblower with the load condition, and increases the sootblowing time and stroke to clean the SCR.

[0027] Step S1: Use a programmable controller to improve the loop.

[0028] Step S2: adjusting the sootblowing time and sootblowing stroke of the sootblower according to the real-time differential pressure data of the SCR and the load condition of the generator set.

[0029] Step S3: The PLC control logic adjusts the sootblowing time and sootblowing stroke parameters of the sootblower according to the real-time load and differential pressure changes.

[0030] Step S4: Automatically adjust the soot blowing time and soot blowing stroke according to the change of the generator set load.

[0031] Step S5: When the SCR differential pressure is too high, increase the soot blowing time or soot blowing stroke.

[0032] Furthermore, in step S1, the programmed controller improves the traditional sootblower circuit by connecting the sootblower, receiving SCR differential pressure data and generator set load data, and performing data processing.

[0033] In step S1, the programmable controller (PLC) improves the traditional sootblower circuit, and the specific implementation method is: the PLC receives the differential pressure data of the SCR and the load data of the generator set in real time by connecting to the control system of the sootblower. The PLC inputs the differential pressure data and load data into the internal processing module, processes them according to these data, and generates control signals. These control signals are used to adjust the sootblowing time and stroke (m and N) of the sootblower. By taking the real-time feedback differential pressure data and load conditions as input, the PLC can automatically adjust the working parameters of the sootblower under different operating conditions. When the SCR differential pressure is too high, the PLC will increase the sootblowing time or stroke to ensure that the accumulated soot is completely removed, thereby effectively reducing the SCR differential pressure. This process does not require manual intervention and is completely completed by the PLC controller based on real-time data. The key technical feature of the PLC is that it can dynamically adjust the operating parameters of the sootblower through precise data processing and control logic to ensure that the SCR can maintain the best working state under various load and differential pressure conditions.

[0034] Furthermore, in step S2, the sootblowing time and sootblowing stroke of the sootblower are dynamically adjusted according to the real-time differential pressure data of the SCR and the load condition of the generator set. If the differential pressure data is slightly abnormal, normal sootblowing is adopted, with continuous advance and retreat; if the differential pressure data is abnormal, short-time fixed-point sootblowing is adopted; if the differential pressure data is seriously abnormal, long-time fixed-point sootblowing is adopted.

[0035] In step S2, when the SCR differential pressure data is slightly abnormal, the soot blower performs normal soot blowing operations and cleans in a "continuous advance, continuous retreat" manner; when the differential pressure data is abnormal, the soot blower switches to short-term fixed-point soot blowing to more accurately target the dust accumulation area; and when the differential pressure data is seriously abnormal, the soot blower performs long-term fixed-point soot blowing to completely remove the dust accumulation and ensure that the catalyst surface is restored to cleanliness. This differential pressure graded soot blowing strategy can dynamically adapt to working conditions of different degrees of blockage, effectively reduce differential pressure, avoid energy waste, and improve the operating efficiency and equipment reliability of the SCR system.

[0036] Furthermore, in step S3, the PLC control logic adjusts the control time and stroke parameters of the sootblower according to the load conditions and SCR differential pressure changes monitored in real time to reduce the differential pressure.

[0037] In step S3, the PLC control logic adjusts the control time and stroke parameters of the soot blower according to the load conditions and air preheater differential pressure changes monitored in real time. Specifically, the PLC continuously obtains the differential pressure data of the air preheater and the load data of the generator set, and judges the changes of the current differential pressure and load in real time. When the differential pressure is too high and the load is high, the PLC will extend the soot blowing time and increase the soot blowing stroke to ensure that the soot blower can fully remove the accumulated dust and reduce the differential pressure; if the differential pressure returns to normal or the load is low, the PLC will shorten the soot blowing time and stroke to avoid excessive soot blowing, save energy and reduce unnecessary soot blowing operations. The PLC adjusts the working state of the soot blower through rapid response and control of real-time data, so that the soot blower can automatically adjust the working parameters according to the actual situation of the air preheater to achieve the best cleaning effect and effectively reduce the situation where the air preheater differential pressure is too high. The core feature of this technology is that the PLC dynamically adjusts the parameters of the soot blower according to the changes in the real-time differential pressure and load, so that the system can efficiently and intelligently remove the accumulated dust under different working conditions, reduce the burden on equipment, and maintain the stable operation of the unit.

[0038] Furthermore, in step S4, the method automatically adjusts the sootblowing time and stroke of the sootblower through PLC, and the working state is matched with the load condition of the generator set in real time.

[0039] In step S4, the method automatically adjusts the sootblowing time and stroke of the sootblower through PLC so that its working state matches the load condition of the generator set in real time. Specifically, PLC obtains the load data of the generator set in real time and dynamically adjusts the working parameters of the sootblower according to the load change. When the load of the unit increases, the system detects that the soot accumulation in the SCR is accelerated, and the PLC will automatically increase the sootblowing time and stroke to ensure that the SCR is fully cleaned; when the load decreases, the soot accumulation rate slows down, and the PLC automatically reduces the sootblowing time and stroke to avoid excessive sootblowing, save energy and reduce unnecessary equipment wear. This process is completed through the internal control logic of the PLC, without the need for human intervention. The sootblower parameters are adjusted through real-time load feedback to keep the sootblowing operation highly synchronized with the load condition of the generator set, thereby ensuring that the cleaning effect of the SCR always matches the load state and improving the economic benefits and operating stability of the generator set.

[0040] Further, in step S5, when the SCR differential pressure exceeds a preset threshold, the PLC enhances the sootblowing effect of the sootblower by increasing the sootblowing time or stroke.

[0041] In step S5, when the SCR differential pressure exceeds the preset threshold, the PLC increases the sootblowing time or sootblowing stroke to enhance the sootblowing effect of the sootblower, ensuring that the SCR is fully cleaned and reducing the differential pressure. Specifically, the PLC monitors the differential pressure data of the SCR in real time. When it detects that the differential pressure exceeds the set threshold, the PLC dynamically adjusts the operating parameters of the sootblower according to the differential pressure. If the differential pressure is higher than the preset threshold, the PLC will increase the sootblowing time, extend the duration of each sootblowing, or increase the sootblowing stroke to ensure that the sootblower can cover more areas of the SCR, thereby effectively removing the accumulated dust. The control logic of the PLC is based on real-time differential pressure data feedback. By accurately adjusting the working parameters of the sootblower, the sootblowing efficiency is automatically improved, the differential pressure is reduced, and the SCR is ensured to be fully cleaned in the shortest time and restored to normal operating conditions.

[0042] Further, the PLC controls the soot blower by executing the G00 group logic, which includes the following steps: Close the sootblower control output (Q02).

[0043] Delay N seconds to control the stroke of the soot blower.

[0044] Disconnect the sootblower control output (Q02).

[0045] Delay M seconds to control the sootblower's sootblowing time on the stroke.

[0046] In this step, the PLC controls the soot blower by executing the G00 group logic. The PLC controls the output Q02 to close and start the soot blower's entry action. Then, the PLC delays for N seconds and controls the soot blower's stroke through this delay time to ensure that the soot blower can move to the predetermined position. After this stroke is completed, the PLC disconnects the control output Q02 and stops the soot blower's entry action. Then, the PLC delays for M seconds and controls the soot blower to perform the soot blowing operation at the current position, that is, the soot blowing time on this stroke. This control logic ensures the working time and stroke of the soot blower under different working conditions through precise delay adjustment, ensuring that each soot blowing can effectively remove the accumulated dust of the SCR, thereby reducing the differential pressure and improving the operating efficiency of the equipment. The feature of this technology is that the soot blower's entry and soot blowing time are controlled by PLC, and the soot blower's stroke and soot blowing process are accurately controlled to avoid excessive or insufficient soot blowing.

[0047] Furthermore, the delay parameters N and M are dynamically adjusted by the PLC according to the real-time differential pressure data of the SCR and the load condition of the generator set.

[0048] In this step, the delay parameters N and M are dynamically adjusted by the PLC according to the real-time differential pressure data of the SCR and the load condition of the generator set. Specifically, the PLC obtains the differential pressure data of the SCR and the load condition data of the generator set in real time, and judges the current condition based on these input data. When the SCR differential pressure is too high and the load condition is high, the PLC will extend the sootblower's stroke delay N and sootblowing time delay M to ensure that the sootblower can provide sufficient cleaning effect, remove dust accumulation and reduce the differential pressure under high load and high differential pressure. Conversely, when the differential pressure is normal or the load is low, the PLC will shorten the delay N and M, reduce the sootblowing time and stroke, thereby avoiding unnecessary sootblowing operations, saving energy and reducing equipment wear. The core feature of this technology is that the PLC dynamically adjusts the delay parameters N and M according to the real-time feedback differential pressure data and load conditions, so that the sootblower can accurately control the sootblowing time and stroke according to the actual situation of the SCR, ensuring the accuracy and efficiency of the sootblowing operation.

[0049] Furthermore, the logic is triggered by conditional judgment, and when the SCR differential pressure exceeds a preset threshold, the G00 group logic is automatically executed to clean the SCR.

[0050] In this step, the logic is triggered by conditional judgment. When the SCR differential pressure exceeds the preset threshold, the PLC automatically executes the G00 group logic to clean the SCR. Specifically, the PLC monitors the differential pressure data of the SCR in real time. When the differential pressure data exceeds the preset threshold, the PLC triggers the conditional judgment and immediately executes the G00 group logic. The logic includes first closing the soot blower control output Q02 to start the soot blower's car entry action; then, the PLC delays N seconds to control the soot blower's stroke to ensure that the soot blower moves to the appropriate position; then, the PLC disconnects the control output Q02 to stop the soot blower's car entry action; finally, the PLC delays M seconds to control the soot blower's soot blowing time at this position to ensure that the accumulated dust is fully removed. Through this control method triggered by conditional judgment, the PLC can automatically start the soot blowing process of the soot blower when the differential pressure is too high, effectively clean the SCR and reduce the differential pressure, and restore the normal operation of the equipment. The technology is characterized in that the precise soot blowing operation is automatically performed through the conditional judgment that the differential pressure exceeds the threshold, ensuring the timely cleaning of the SCR, avoiding manual intervention, and improving the automation and operation efficiency of the system.

[0051] The changes of step-by-step sootblowing are shown in Table 1 below: time #2 unit meets (MW) SCR differential pressure before transformation (Pa) SCR differential pressure after transformation (Pa) 1 549.0 811 579 2 549.5 811 579 3 550.0 812 580 4 550.5 812 580 Table 1: Changes of SCR before and after soot blowing in #2 furnace After three times of step-by-step soot blowing, the SCR differential pressure dropped from 812Pa to 580Pa under a load of 550, a decrease of about 28%. Good results were achieved.

[0052] Those skilled in the art should understand that the various embodiments disclosed above can be changed and modified in various ways without departing from the essence of the invention. Therefore, the protection scope of the present invention should be defined by the appended claims.

[0053] It should be noted that not all steps and units in the above processes are necessary, and some steps or units can be ignored according to actual needs. The execution order of each step is not fixed and can be determined as needed. The device structure described in the above embodiments can be a physical structure or a logical structure, that is, some units may be implemented by the same physical entity, or some units may be implemented by multiple physical entities, or some components in multiple independent devices may be implemented together.

[0054] The specific embodiments set forth above describe exemplary embodiments, but do not represent all embodiments that may be implemented or fall within the scope of protection of the claims. The term "exemplary" used throughout this specification means "used as an example, instance, or illustration" and does not mean "preferred" or "having advantages" over other embodiments. For the purpose of providing an understanding of the described techniques, the specific embodiments include specific details. However, these techniques may be implemented without these specific details. In some instances, in order to avoid obscuring the concepts of the described embodiments, well-known structures and devices are shown in block diagram form.

[0055] The above description of the present disclosure is provided to enable any person of ordinary skill in the art to implement or use the present disclosure. Various modifications to the present disclosure will be apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of protection of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but is consistent with the widest range of principles and novel features disclosed herein.

Claims

1. A SCR differential pressure optimization control method based on a program-controlled sootblower, characterized by: PLC improves sootblower circuit and data processing, dynamically adjusts sootblowing time and sootblowing stroke, PLC control logic adjusts sootblowing parameters, automatically matches sootblower and load conditions, and increases sootblowing time and stroke to clean SCR; Step S1: Use a programming controller to improve the circuit; Step S2: adjusting the sootblowing time and sootblowing stroke of the sootblower according to the real-time differential pressure data of the SCR and the load condition of the generator set; Step S3: PLC control logic adjusts the sootblowing time and sootblowing stroke parameters of the sootblower according to the real-time load and differential pressure changes; Step S4: Automatically adjust the soot blowing time and soot blowing stroke according to the change of the generator set load; Step S5: When the SCR differential pressure is too high, increase the soot blowing time or soot blowing stroke.

2. The SCR differential pressure optimization control method based on program-controlled sootblower according to claim 1 is characterized in that: In step S1, the programmable controller improves the traditional soot blower circuit by connecting the soot blower, receiving SCR differential pressure data and generator set load data, and performing data processing.

3. The SCR differential pressure optimization control method based on program-controlled sootblower according to claim 1 is characterized in that: In step S2, the sootblowing time and sootblowing stroke of the sootblower are dynamically adjusted according to the real-time differential pressure data of the SCR and the load condition of the generator set. If the differential pressure data is slightly abnormal, normal sootblowing is adopted, with continuous advance and continuous retreat; if the differential pressure data is abnormal, short-time fixed-point sootblowing is adopted; if the differential pressure data is seriously abnormal, long-time fixed-point sootblowing is adopted.

4. The SCR differential pressure optimization control method based on program-controlled sootblower according to claim 1 is characterized in that: In step S3, the PLC control logic adjusts the control time and stroke parameters of the sootblower according to the load conditions and SCR differential pressure changes monitored in real time to reduce the differential pressure.

5. The SCR differential pressure optimization control method based on program-controlled sootblower according to claim 1 is characterized in that: In step S4, the method automatically adjusts the sootblowing time and stroke of the sootblower through PLC, and the working state is matched with the load condition of the generator set in real time.

6. The SCR differential pressure optimization control method based on program-controlled sootblower according to claim 1 is characterized in that: In step S5, when the SCR differential pressure exceeds a preset threshold, the PLC enhances the sootblowing effect of the sootblower by increasing the sootblowing time or stroke.

7. The SCR differential pressure optimization control method based on program-controlled sootblower according to claim 1 is characterized by: The PLC controls the soot blower by executing the G00 group logic, which includes the following steps: Close sootblower control output (Q02); Delay N seconds to control the stroke of the soot blower; Disconnect the sootblower control output (Q02); Delay M seconds to control the sootblower's sootblowing time on the stroke.

8. The SCR differential pressure optimization control method based on program-controlled sootblower according to claim 1 is characterized by: The delay parameters N and M are dynamically adjusted by the PLC according to the real-time differential pressure data of the SCR and the load condition of the generator set.

9. The SCR differential pressure optimization control method based on program-controlled sootblower according to claim 1 is characterized by: The logic is triggered by conditional judgment. When the SCR differential pressure exceeds a preset threshold, the G00 group logic is automatically executed to clean the SCR.

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