Blowback monitoring and alarming method and system for bag filter

Abstract

The invention discloses a blowback monitoring and alarming method and system for a bag filter, and belongs to the field of coal gasification combined cycle power generation, and the method comprises the steps: obtaining first change data of an electromagnetic valve through a PLC of the bag filter; a pressure transmitter is connected to the PLC, and second change data of the nitrogen mother pipe are obtained through the first change data; setting a pressure drop threshold value according to the second change data, associating the pressure drop threshold value with a blowback air inflow, and carrying out a blowback action; when the pressure drop is lower than a threshold value, the PLC gives an abnormal alarm; and the abnormal electromagnetic valve is positioned according to the second change data point giving the alarm. The defects of equipment installation of an original filtering system are overcome, an alarm can be given out in time for tiny abnormity of the blowback system, and a reliable basis is provided for operation and maintenance of the equipment. Meanwhile, each action of each blowback pulse valve can be monitored, and normal and stable work of the pulse valves is guaranteed. And the device has a very high popularization value for optimization and improvement of a bag type dust filtering system.

Description

Technical Field

[0001] The invention relates to the field of coal gasification combined cycle power generation, and in particular to a back-flushing monitoring and alarm method and system for a bag filter. Background Art

[0002] The original IGCC unit bag filter backwash had no monitoring conditions, and it was impossible to monitor whether the pulse solenoid valve command was issued, the backwash valve operation status, and the backwash effect.

[0003] The original IGCC unit bag filter backflush had no monitoring conditions, and it was impossible to monitor whether the pulse solenoid valve command was issued, whether the backflush valve was operating, and the backflush effect. Backflush system problems can cause the bags to burn and cause equipment to shut down. In addition, the dust content during bag repair and replacement is high, which is a major hidden danger operation. Summary of the invention

[0004] In view of the above existing problems, the present invention aims to solve the problem of unmonitored backwashing of bag filters in IGCC units.

[0005] In order to solve the above technical problems, a backwash monitoring and alarm method for bag filter is proposed, comprising:

[0006] The first change data of the solenoid valve is obtained through the PLC of the bag filter; the pressure transmitter is connected to the PLC to obtain the second change data of the nitrogen main pipe through the first change data; the pressure drop threshold is set according to the second change data, and it is associated with the back-blowing air intake volume to carry out the back-blowing action; when the pressure drop is lower than the threshold, the PLC issues an abnormal alarm; the abnormal solenoid valve is located according to the second change data point that issues the alarm.

[0007] As a preferred solution of the bag filter backwash monitoring and alarm method described in the present invention, the first change data includes the action change instruction of the solenoid valve, and the second change data includes the nitrogen main pipe pressure change value for each backwash solenoid valve opening instruction from the issuance to the end time period.

[0008] As a preferred solution of the back-blowing monitoring and alarm method for bag filters described in the present invention, wherein: the PLC sends out an abnormal alarm including recording the mother pipe pressure while issuing the first solenoid valve opening command, and when the valve opening command signal arrives, the solenoid valve drives the back-blowing valve to operate, and after the valve is opened, the nitrogen self-reforming valve of the mother pipe enters the purge pipeline for purge, and the mother pipe pressure drops to a maximum value and then slowly rises until the valve opening command disappears and the valve is closed, and the nitrogen mother pipe pressure continues to rise to the journey value until the second solenoid valve opening command is issued, and the mother pipe pressure no longer changes;

[0009] Set the action interval between the first electromagnetic valve and the second electromagnetic valve to t, where t is the entire action cycle of the first electromagnetic valve;

[0010] If the backflush is normal within the t cycle, the pressure drop value exceeds the threshold a for a short time, and the pressure drop value is subtracted from the threshold a. The comparison block function is used. When the pressure drop value is less than the threshold a, the comparison block output is connected to the S_ODT on-delay timer inside the PLC. At this time, the on-delay timer is triggered. If the trigger time is greater than or equal to t, an alarm is issued to indicate that the valve action is abnormal.

[0011] If the valve operates normally, the delay timer trigger time will be less than t, and the alarm signal will not be triggered, and the valve operates normally;

[0012] Determine the first back-blowing action of each solenoid valve, issue an alarm when an abnormality occurs, and determine the valve number of the abnormal solenoid valve in combination with the valve opening instruction model of the solenoid valve.

[0013] As a preferred solution of the back-blowing monitoring and alarm method for bag filter described in the present invention, the back-blowing action includes: when the pressure drop is higher than the threshold value a, it is considered that the larger the back-blowing air intake volume, the better the back-blowing effect;

[0014] When the pressure drop is lower than the threshold a, it is considered that the backflush effect is poor, and an abnormal alarm is issued to prompt the operation and maintenance personnel to deal with the abnormal backflush defects, and the PLC output relay controls the backflush action;

[0015] The back-blowing action is to open the back-blowing pulse valve, start back-blowing the air until the pressure transmitter transmits it to the PLC to show that the nitrogen main pipe pressure is reduced. When the nitrogen main pipe pressure is reduced to the threshold value b, the back-blowing pulse valve is closed, and the main pipe pressure is restored at this time;

[0016] The back-flushing pulse valves in each row of the solenoid valves perform back-flushing actions one by one, and back-flushing with the filter bags in their corresponding columns respectively, to obtain the first back-flushing results and construct a pressure monitoring curve.

[0017] As a preferred solution of the back-blowing monitoring and alarm method for bag filter described in the present invention, wherein: the pressure monitoring curve includes, the pressure monitoring curve constructed according to the first back-blowing result is divided into an upper gas source main pipe and lower two side gas source main pipes;

[0018] The position where the lowest value of the back-blowing pulse valve in a row corresponding to the upper gas source mother pipe is greater than the average lowest value indicates that the filter bag cannot be effectively back-blown for the second time, and the fault needs to be eliminated, and an alarm is issued to indicate the second type of abnormality;

[0019] The position where the lowest value in the row of back-blowing pulse valves corresponding to the lower air source mother pipe is less than the average lowest value indicates that the back-blowing air pressure is insufficient, and the filter bag cannot be effectively subjected to a second back-blowing action. The fault needs to be eliminated, and an alarm is issued to prompt the second type of abnormality.

[0020] As a preferred solution of the back-blowing monitoring and alarm method for bag filters described in the present invention, the second back-blowing action includes opening and closing two back-blowing pulse valves in each column at the same time, and performing the second back-blowing action, i.e., back-blowing and cleaning, on the filter bags corresponding to the spray pipes in the same column;

[0021] The PLC sends a valve opening command to one of the valves, the corresponding valve opens, and nitrogen enters the bag of the bag filter from the valve body through the main pipe, and backwashing begins;

[0022] When the nitrogen consumption is greater than the amount of gas supplied from the gas storage tank to the main pipe, the nitrogen main pipe pressure decreases, resulting in a pressure drop. As the valve opening time and nitrogen consumption increase, the main pipe pressure drop tends to increase slowly. After reaching the maximum value, the nitrogen consumption pressure drop in the main pipe gradually decreases.

[0023] If the blowback valve refuses to operate, the pressure drop will always be zero during the current valve operation cycle;

[0024] If the back-blowing valve opens for a short time, the back-blowing air intake will be small, affecting the back-blowing effect, and the pressure drop will be manifested as a small peak value;

[0025] If the back-blowing valve takes a long time to open or cannot be closed after opening, the current valve will continue to be back-blown, causing the main pipe pressure to be too low and unable to return to the initial pressure value for a long time, causing the corresponding back-blowing pressure drop to be too low or zero when the next back-blowing valve is actuated;

[0026] According to the result of the second backflush action, adjust the first backflush action and judge the rationality of the backflush action.

[0027] As a preferred solution of the backwash monitoring and alarm method for bag filter described in the present invention, the rationality of the backwash action includes checking and verifying whether the setting of the parameters of the lowered alarm value and the alarm judgment time is reasonable according to the actual backwash effect, evaluating the backwash effect by monitoring the change of the main pipe pressure of each backwash valve during the action, calculating the pressure drop ΔP and evaluating the alarm judgment time T judgment ;

[0028] When ΔP ≥ T alarm And T judgment When <0, it means the backflush effect is good and a normal signal is issued;

[0029] When ΔP <T alarm or T judgment When ≥0, the backflush effect is considered poor, an alarm is triggered, and maintenance operations are prompted. alarm Used to determine whether the backflush effect reaches the standard pressure drop value.

[0030] Another object of the present invention is to provide a back-blowing monitoring and alarm system for bag filters. The purpose of the present invention is to monitor the operating status of the bag filter in real time, including obtaining the change data of the solenoid valve and the nitrogen main pipe, and setting the pressure drop threshold according to the pressure change of the nitrogen main pipe to automatically control the back-blowing action to remove the dust accumulated on the filter and maintain the filtering effect; at the same time, when the pressure drop is lower than the set threshold, the system can automatically issue an abnormal alarm and locate the abnormal solenoid valve, thereby ensuring the normal operation and efficiency of the bag filter, improving the degree of automation, ensuring the continuity and stability of the production process, and reducing maintenance costs and troubleshooting time.

[0031] As a preferred solution of the bag filter backflush monitoring and alarm system described in the present invention, it is characterized by comprising a change data acquisition module, a backflush module and an alarm module;

[0032] The change data acquisition module acquires the first change data of the solenoid valve through the PLC of the bag filter, connects the pressure transmitter to the PLC, and acquires the second change data of the nitrogen main pipe through the first change data;

[0033] The back-blowing module sets a pressure drop threshold according to the second change data, associates it with the back-blowing air intake volume, and performs a back-blowing action;

[0034] The alarm module, when the pressure drop is lower than the threshold, the PLC issues an abnormal alarm and locates the abnormal solenoid valve according to the second change data point at which the alarm is issued.

[0035] A computer device includes a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of the bag filter backwash monitoring and alarm method are implemented.

[0036] A computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps of a bag filter backwash monitoring and alarm method are implemented.

[0037] Beneficial effects of the invention: The invention optimizes the defects of the original filtration system equipment installation. The optimization and transformation of the control system conducts comprehensive status monitoring of the bag filter system, and can promptly issue an alarm for minor abnormalities in the back-blowing system, providing a reliable basis for the operation and maintenance of the equipment. At the same time, it can monitor every action of each back-blowing pulse valve to ensure the normal and stable operation of the pulse valve. It has a high promotion value for the optimization and improvement of the bag dust filtration system. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0039] Figure 1 An overall flow chart of a bag filter backflushing monitoring and alarm method provided by one embodiment of the present invention.

[0040] Figure 2 A backwash pressure drop curve diagram for a bag filter backwash monitoring and alarm method provided by one embodiment of the present invention.

[0041] Figure 3 An example diagram of a PLC logic backwash abnormal alarm for a bag filter backwash monitoring and alarm method provided by an embodiment of the present invention.

[0042] Figure 4 A system solution module diagram for a bag filter backwash monitoring and alarm system provided in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0044] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0045] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is mutually exclusive with other embodiments, either individually or selectively.

[0046] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0047] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are 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 direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0048] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] Example 1, reference Figure 1-Figure 2 , which is the first embodiment of the present invention, provides a bag filter backwash monitoring and alarm method, comprising:

[0050] According to conventional thinking logic, the most direct way to determine whether the valve action is normal is to add an open position feedback device to each back-blowing solenoid valve, and determine whether the back-blowing solenoid valve is operating normally through the solenoid valve opening command and the open feedback signal. The normal delivery of the open feedback signal is used as the basis for judging whether the back-blowing solenoid valve is operating normally and the filter is back-blowing normally. During the discussion and verification process, this method not only requires adding an open position detection device to each back-blowing valve, but also requires laying cables to transmit the valve position feedback signal to the PLC and adding a large number of PLC switch input cards. This solution requires a large amount of engineering construction and is expensive. This detection method can only detect whether the back-blowing valve is operating normally, but cannot detect the actual back-blowing effect (back-blowing air intake).

[0051] Using the original PLC of the bag filter, the pressure of the nitrogen main pipe from the time when each back-blowing solenoid valve is opened to the time when it is closed is fully detected and measured, and all are transmitted to the inside of the PLC. Considering that the 28 branch back-blowing nitrogen pipelines controlled by the 28 solenoid valves in a filter are all from the same nitrogen main pipe, when any solenoid valve is actuated for back-blowing, the nitrogen in the nitrogen main pipe will inevitably cause the main pipe pressure to decrease because the back-blowing consumption is greater than the gas replenishment volume of the gas tank. This pressure reduction value is the pressure drop. The value of the pressure drop when the back-blowing valve is actuated can indirectly reflect the back-blowing effect (back-blowing air intake). Theoretically speaking, the greater the pressure drop of the main pipe during back-blowing, the greater the back-blowing air intake, and the better the back-blowing effect. We can set a fixed value for this pressure drop. When the pressure drop value is lower than the fixed value, it is considered that the back-blowing effect is poor and an abnormal alarm is issued, and the back-blowing solenoid valve is finally determined to be abnormal based on the back-blowing valve action instruction at this time.

[0052] S1: Acquire the first change data of the solenoid valve through the PLC of the bag filter.

[0053] Specifically, the first change data includes the action change instruction of the solenoid valve, and the second change data includes the nitrogen main pipe pressure change value for each back-blowing solenoid valve opening instruction during the time period from when the back-blowing solenoid valve opening instruction is issued to when the instruction ends.

[0054] S2: Connect the pressure transmitter to the PLC to obtain the second change data of the nitrogen main pipe through the first change data.

[0055] S3: Set the pressure drop threshold according to the second change data, associate it with the back-blowing air intake volume, and carry out the back-blowing action. The abnormal alarm issued by the PLC includes recording the mother pipe pressure while the first solenoid valve opening command is issued. When the valve opening command signal arrives, the solenoid valve drives the back-blowing valve to operate. After the valve is opened, the nitrogen self-reforming valve of the mother pipe enters the purge pipeline for purge. After the mother pipe pressure drops to the maximum value, it slowly rises until the valve opening command disappears and the valve is closed. The nitrogen mother pipe pressure continues to rise to the journey value until the second solenoid valve opening command is issued, and the mother pipe pressure no longer changes;

[0056] Set the action interval between the first electromagnetic valve and the second electromagnetic valve to t, where t is the entire action cycle of the first electromagnetic valve;

[0057] If the backflush is normal within the t cycle, the pressure drop value exceeds the threshold a for a short time, and the pressure drop value is subtracted from the threshold a. The comparison block function is used. When the pressure drop value is less than the threshold a, the comparison block output is connected to the S_ODT on-delay timer inside the PLC. At this time, the on-delay timer is triggered. If the trigger time is greater than or equal to t, an alarm is issued to indicate that the valve action is abnormal.

[0058] If the valve operates normally, the delay timer trigger time will be less than t, and the alarm signal will not be triggered, and the valve operates normally;

[0059] Determine the first back-blowing action of each solenoid valve, issue an alarm when an abnormality occurs, and determine the valve number of the abnormal solenoid valve in combination with the valve opening instruction model of the solenoid valve.

[0060] The back-blowing action includes: when the pressure drop is higher than a threshold value a, it is considered that the larger the back-blowing air intake volume is, the better the back-blowing effect is;

[0061] When the pressure drop is lower than the threshold a, it is considered that the backflush effect is poor, and an abnormal alarm is issued to prompt the operation and maintenance personnel to deal with the abnormal backflush defects, and the PLC output relay controls the backflush action;

[0062] The back-blowing action is to open the back-blowing pulse valve, start back-blowing the air until the pressure transmitter transmits it to the PLC to show that the nitrogen main pipe pressure is reduced. When the nitrogen main pipe pressure is reduced to the threshold value b, the back-blowing pulse valve is closed, and the main pipe pressure is restored at this time;

[0063] The back-flushing pulse valves in each row of the solenoid valves perform back-flushing actions one by one, and back-flushing with the filter bags in their corresponding columns respectively, to obtain the first back-flushing results and construct a pressure monitoring curve.

[0064] Specifically, the pressure monitoring curve includes a pressure monitoring curve constructed according to the first backflush result and is divided into an upper gas source mother pipe and lower two side gas source mother pipes;

[0065] The position where the lowest value of the back-blowing pulse valve in a row corresponding to the upper gas source mother pipe is greater than the average lowest value indicates that the filter bag cannot be effectively back-blown for the second time, and the fault needs to be eliminated, and an alarm is issued to indicate the second type of abnormality;

[0066] The position where the lowest value in the row of back-blowing pulse valves corresponding to the lower air source mother pipe is less than the average lowest value indicates that the back-blowing air pressure is insufficient, and the filter bag cannot be effectively subjected to a second back-blowing action. The fault needs to be eliminated, and an alarm is issued to prompt the second type of abnormality.

[0067] It should be noted that the two back-blowing pulse valves in each column are opened and closed at the same time, and the filter bags corresponding to the injection pipes in the same column are subjected to the second back-blowing action, i.e., back-blowing cleaning.

[0068] The PLC sends a valve opening command to one of the valves, the corresponding valve opens, and nitrogen enters the bag of the bag filter from the valve body through the main pipe, and backwashing begins;

[0069] When the nitrogen consumption is greater than the amount of gas supplied from the gas storage tank to the main pipe, the nitrogen main pipe pressure decreases, resulting in a pressure drop. As the valve opening time and nitrogen consumption increase, the main pipe pressure drop tends to increase slowly. After reaching the maximum value, the nitrogen consumption pressure drop in the main pipe gradually decreases.

[0070] If the blowback valve refuses to operate, the pressure drop will always be zero during the current valve operation cycle;

[0071] If the back-blowing valve opens for a short time, the back-blowing air intake will be small, affecting the back-blowing effect, and the pressure drop will be manifested as a small peak value;

[0072] If the back-blowing valve opens for a long time or cannot be closed after opening, the current valve will continue to intake air for back-blowing, causing the main pipe pressure to be too low and unable to return to the initial pressure value for a long time, resulting in the corresponding back-blowing pressure drop being too low or zero when the next back-blowing valve is actuated. This enables the working status of each back-blowing pulse valve in the filtration system to be monitored, so that an alarm can be immediately issued when a back-blowing pulse valve is in an abnormal state, and disposal can be carried out to avoid filter bag burning, greatly reducing manpower and material losses.

[0073] According to the result of the second backflush action, adjust the first backflush action and judge the rationality of the backflush action.

[0074] According to the actual back-blowing effect, check and verify whether the settings of the lower alarm value and alarm judgment time parameters are reasonable. By monitoring the changes in the main pipe pressure of each back-blowing valve during the operation, the back-blowing effect can be evaluated and the pressure drop can be calculated:

[0075]

[0076] Among them, ΔP is the pressure drop during the back-blowing process, which indicates the pressure difference when the back-blowing valve is opened; K is a constant corresponding to the equipment characteristics and fluid properties, reflecting the relationship between pressure loss and fluid parameters. Equipment characteristics include pipeline diameter and fluid type, and fluid properties include nitrogen density and viscosity; P0 is the main pipe pressure before the back-blowing valve is opened, that is, the static pressure value before back-blowing; P f is the lowest main pipe pressure after the backwash valve is opened, indicating the pressure drop caused by the flow of nitrogen during the backwash process; α indicates the contribution of nitrogen flow to the pressure drop, Q(t is the nitrogen flow function flowing through the backwash process, describing the flow value at time t; t1 and t2 are the time boundaries of the backwash process, indicating the start and end time points of the backwash process, respectively; Indicates the total nitrogen flow rate passing through during the current time;

[0077] Evaluation alarm judgment time:

[0078]

[0079] Among them, T judgment Indicates the time to judge the rationality of the backflush effect, that is, the alarm judgment time that actually needs to be monitored; T alarm It is used to judge whether the backflush effect reaches the standard pressure drop value. β represents the adjustment coefficient of the impact of flow change on the alarm judgment time.

[0080] When ΔP ≥ T alarm And T judgmentWhen <0, it means the backflush effect is good and a normal signal is issued;

[0081] When ΔP <T alarm or T judgment When ≥0, the backflush effect is considered poor, an alarm is triggered, and maintenance operations are prompted.

[0082] S4: When the voltage drop is lower than the threshold, the PLC issues an abnormal alarm.

[0083] S5: Locate the abnormal solenoid valve according to the second change data point that issues an alarm.

[0084] Take the pulse valve with an action pulse of 120ms and an action interval of 13S as an example. Figure 3 As shown, the corresponding PLC internal logic is expressed as:

[0085] When the valve opening command of valve #1 is issued, the main pipe pressure P0 is recorded. Then the valve opening command signal reaches the solenoid valve to drive the back-blowing valve to operate. After the valve is opened, the nitrogen in the main pipe automatically enters the purge pipeline for purge. At this time, the main pipe pressure will slowly drop to the maximum value and then slowly rise again until the valve opening command disappears and the valve is closed. The nitrogen main pipe pressure continues to rise to the normal value.

[0086] This process is generally longer than the solenoid valve opening time, and the pressure recovery will be delayed. Until the 2# solenoid valve opening command is issued, the main pipe pressure will not change.

[0087] According to the existing logic, the action interval between 1# and 2# solenoid valves is 13S, and this 13S is the entire action cycle of 1# valve.

[0088] If the backflush is normal within this cycle, the pressure drop value will exceed the alarm setting value for a short time. At this time, we use the pressure drop value and the alarm setting value to make a difference, use the comparison block function, and output 1 when the pressure drop value is less than the alarm setting value. The comparison block output is connected to the S inside the PLC. ODT Turn on the delay timer.

[0089] According to the above working principle, if the solenoid valve does not work or the valve is opened too short (the air intake is too small), the comparison block will always output 1 during the valve action cycle (13s). At this time, the delay timer is triggered, and the trigger time is 13S. If it is greater than or equal to the setting of 13S, an alarm will be issued to indicate that the valve action is abnormal.

[0090] If the valve operates normally, the delay timer trigger time will be less than the set value of 13S. At this time, the alarm signal will not be triggered and the valve operates normally.

[0091] In this way, the action status (backblowing status) of each solenoid valve is judged one by one, and an alarm is issued when an abnormality occurs. The valve number of the abnormal solenoid valve can be determined in combination with the valve opening instruction model of the solenoid valve, providing a reliable basis for monitoring and troubleshooting.

[0092] Embodiment 2, the second embodiment of the present invention, is different from the first two embodiments in that:

[0093] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program codes.

[0094] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0095] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0096] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0097] Example 3, reference Figure 4 , which is the third embodiment of the present invention, and provides a bag filter backwash monitoring and alarm system, including a change data acquisition module 10, a backwash module 20 and an alarm module 30;

[0098] The change data acquisition module 10 acquires the first change data of the solenoid valve through the PLC of the bag filter, connects the pressure transmitter to the PLC, and acquires the second change data of the nitrogen main pipe through the first change data;

[0099] The back-blowing module 20 sets a pressure drop threshold according to the second change data, associates it with the back-blowing air intake volume, and performs a back-blowing action;

[0100] When the pressure drop of the alarm module 30 is lower than the threshold, the PLC issues an abnormal alarm and locates the abnormal solenoid valve according to the second change data point at which the alarm is issued.

[0101] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A bag filter backflush monitoring and alarm method, characterized in that: include, Acquire first change data of the solenoid valve through the PLC of the bag filter; Connect the pressure transmitter to the PLC to obtain the second change data of the nitrogen main pipe through the first change data; The pressure drop threshold is set according to the second change data, and is associated with the back-blowing air intake volume to carry out the back-blowing action; When the voltage drop is lower than the threshold, the PLC will issue an abnormal alarm; The abnormal solenoid valve is located according to the second change data point that issues an alarm.

2. A bag filter backflush monitoring and alarm method as claimed in claim 1, characterized in that: The first change data includes the action change instruction of the solenoid valve, and the second change data includes the nitrogen main pipe pressure change value for each back-blowing solenoid valve opening instruction during the period from the issuance to the end.

3. A bag filter backflush monitoring and alarm method as claimed in claim 2, characterized in that: The abnormal alarm issued by the PLC includes recording the mother pipe pressure while issuing the first solenoid valve opening command, and when the valve opening command signal arrives, the solenoid valve drives the back-blowing valve to act, and after the valve is opened, the nitrogen self-reforming valve of the mother pipe enters the purge pipeline for purge, and the mother pipe pressure drops to a maximum value and then slowly rises until the valve opening command disappears and the valve is closed, and the nitrogen mother pipe pressure continues to rise to the journey value until the second solenoid valve opening command is issued, and the mother pipe pressure no longer changes; Set the action interval between the first electromagnetic valve and the second electromagnetic valve to t, where t is the entire action cycle of the first electromagnetic valve; If the backflush is normal within the t cycle, the pressure drop value exceeds the threshold a for a short time, and the pressure drop value is subtracted from the threshold a. The comparison block function is used. When the pressure drop value is less than the threshold a, the comparison block output is connected to the S_ODT on-delay timer inside the PLC. At this time, the on-delay timer is triggered. If the trigger time is greater than or equal to t, an alarm is issued to indicate that the valve action is abnormal. If the valve operates normally, the delay timer trigger time will be less than t, and the alarm signal will not be triggered, and the valve operates normally; Determine the first back-blowing action of each solenoid valve, issue an alarm when an abnormality occurs, and determine the valve number of the abnormal solenoid valve in combination with the valve opening instruction model of the solenoid valve.

4. A bag filter backflush monitoring and alarm method as claimed in claim 3, characterized in that: The back-blowing action includes: when the pressure drop is higher than a threshold value a, it is considered that the larger the back-blowing air intake volume is, the better the back-blowing effect is; When the pressure drop is lower than the threshold a, it is considered that the backflush effect is poor, and an abnormal alarm is issued to prompt the operation and maintenance personnel to deal with the abnormal backflush defects, and the PLC output relay controls the backflush action; The back-blowing action is to open the back-blowing pulse valve, start back-blowing the air until the pressure transmitter transmits it to the PLC to show that the nitrogen main pipe pressure is reduced. When the nitrogen main pipe pressure is reduced to the threshold value b, the back-blowing pulse valve is closed, and the main pipe pressure is restored at this time; The back-flushing pulse valves in each row of the solenoid valves perform back-flushing actions one by one, and back-flushing with the filter bags in their corresponding columns respectively, to obtain the first back-flushing results and construct a pressure monitoring curve.

5. A bag filter backflush monitoring and alarm method as claimed in claim 4, characterized in that: The pressure monitoring curve includes a pressure monitoring curve constructed according to the first backflush result and divided into an upper gas source mother pipe and lower two side gas source mother pipes; The position where the lowest value of the back-blowing pulse valve in a row corresponding to the upper gas source mother pipe is greater than the average lowest value indicates that the filter bag cannot be effectively back-blown for the second time, and the fault needs to be eliminated, and an alarm is issued to indicate the second type of abnormality; The position where the lowest value in the row of back-blowing pulse valves corresponding to the lower air source mother pipe is less than the average lowest value indicates that the back-blowing air pressure is insufficient, and the filter bag cannot be effectively subjected to a second back-blowing action. The fault needs to be eliminated, and an alarm is issued to prompt the second type of abnormality.

6. A bag filter backflush monitoring and alarm method as claimed in claim 5, characterized in that: The second back-blowing action includes opening and closing two back-blowing pulse valves in each column at the same time, and performing the second back-blowing action, i.e., back-blowing cleaning, on the filter bags corresponding to the injection pipes in the same column; The PLC sends a valve opening command to one of the valves, the corresponding valve opens, and nitrogen enters the bag of the bag filter from the valve body through the main pipe, and backwashing begins; When the nitrogen consumption is greater than the amount of gas supplied from the gas storage tank to the main pipe, the nitrogen main pipe pressure decreases, resulting in a pressure drop. As the valve opening time and nitrogen consumption increase, the main pipe pressure drop tends to increase slowly. After reaching the maximum value, the nitrogen consumption pressure drop in the main pipe gradually decreases. If the blowback valve refuses to operate, the pressure drop will always be zero during the current valve operation cycle; If the back-blowing valve opens for a short time, the back-blowing air intake will be small, affecting the back-blowing effect, and the pressure drop will be manifested as a small peak value; If the back-blowing valve takes a long time to open or cannot be closed after opening, the current valve will continue to be back-blown, causing the main pipe pressure to be too low and unable to return to the initial pressure value for a long time, causing the corresponding back-blowing pressure drop to be too low or zero when the next back-blowing valve is actuated; According to the result of the second backflush action, adjust the first backflush action and judge the rationality of the backflush action.

7. A bag filter backflush monitoring and alarm method as claimed in claim 6, characterized in that: The rationality of the back-blowing action includes checking and verifying whether the setting of the parameters of reducing the alarm value and the alarm judgment time is reasonable according to the actual back-blowing effect, evaluating the back-blowing effect by monitoring the changes in the main pipe pressure of each back-blowing valve during the action, calculating the pressure drop ΔP and evaluating the alarm judgment time T judgment ; When ΔP ≥ T alarm And T judgment When <0, it means the backflush effect is good and a normal signal is issued; When ΔP <T alarm or T judgment When ≥0, the backflush effect is considered poor, an alarm is triggered, and maintenance operations are prompted. alarm Used to determine whether the backflush effect reaches the standard pressure drop value.

8. A system using a bag filter backflush monitoring and alarm method as claimed in any one of claims 1 to 7, characterized in that: It includes a change data acquisition module, a backflush module and an alarm module; The change data acquisition module acquires the first change data of the solenoid valve through the PLC of the bag filter, connects the pressure transmitter to the PLC, and acquires the second change data of the nitrogen main pipe through the first change data; The back-blowing module sets a pressure drop threshold according to the second change data, associates it with the back-blowing air intake volume, and performs a back-blowing action; The alarm module, when the pressure drop is lower than the threshold, the PLC issues an abnormal alarm and locates the abnormal solenoid valve according to the second change data point at which the alarm is issued.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of a bag filter backwash monitoring and alarm method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a bag filter backwash monitoring and alarm method according to any one of claims 1 to 7 are implemented.

Images