Clean and energy-saving control system and control method for industrial dust removal exhaust system

Abstract

The invention relates to the technical field of industrial dust removal, in particular to a cleaning and energy-saving control system and method for an industrial dust removal exhaust system, and the system comprises a bag-type dust collector which is provided with a gas inlet, a gas outlet, a backflushing port and a dust collection part, and is internally provided with a plurality of dust collection bags; industrial waste gas entering from the gas inlet flows out from the gas outlet after being filtered by the dust removal cloth bag. According to the control system, different preset operation frequency parameters of the variable-frequency fan are correspondingly set according to the opening number of the flap valves, after the variable-frequency fan reaches the preset parameters, automatic adjustment is carried out through the pressure difference, and through the pressure adjustment mode combining parameter presetting and PID adjustment, the dust removal efficiency is improved in the starting process of the dust removal system. And the corresponding gulp valve and fan frequency preset values are quickly matched to cope with the change of the tail end point position, and oscillation and overshoot are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial dust removal, and in particular to a clean and energy-saving control system and a control method for an industrial dust removal and exhaust system. Background Art

[0002] Modern iron and steel metallurgical enterprises and chemical enterprises generate a lot of dust and other pollutants during the production process, especially in the pre-treatment, crushing, sintering and other areas. During the transportation of block or powder materials, a lot of dust pollutants will be generated, which will pollute the surrounding environment. Moreover, the dust particles are small in size and have many components, which can easily cause inhalation injuries to the operators of the enterprise.

[0003] As the country has elevated green development and ecological improvement to a national strategic level, the control of particulate pollutant emissions has received more and more attention. Conventional dust removal methods are difficult to solve the environmental protection requirements of air pollution prevention and control and clean green production in some industrial enterprises with many dust sources and large amounts of dust, and there is also the problem of excessive consumption of electric energy. In steel enterprises, the energy consumption of dust removal fan systems accounts for a considerable proportion of the total energy consumption, so energy saving in dust removal systems helps enterprises save energy and reduce emissions and enhance industry competitiveness.

[0004] At present, a dust removal system consisting of a negative pressure fan and a bag dust collector is usually used for industrial dust removal, but this system has the following defects:

[0005] According to the design specifications and the perspective of safe production, various problems that may occur during long-term operation are considered in the design of the dust removal system. The maximum air volume and air pressure under the most unfavorable conditions of the system are usually used as the basis for selection. Generally, a 15-20% design margin is reserved for air volume and a 10% margin is reserved for air pressure. As a result, the dust removal fan system generally has low operating efficiency. In actual production, the fan capacity is often much larger than the actual demand.

[0006] With the change of the terminal synchronous online working point, the change of the dust volume and temperature of the dust removal system, the demand for dust removal exhaust air volume changes, and then the negative pressure of the pipeline changes accordingly. If the aerodynamic performance of the dust removal fan cannot adapt to and follow this change, and quickly compensate or suppress the sharp increase or decrease of the pipeline pressure, the dust at the dust collection point will escape or be over-absorbed, which will not achieve the expected dust removal effect, and the fan operating efficiency of the dust removal system will be reduced, resulting in increased system energy consumption. Summary of the invention

[0007] In view of the technical problems existing in the dust removal system in the prior art, the first aspect of the present invention proposes a clean and energy-saving control system for an industrial dust removal and exhaust system, comprising:

[0008] The bag dust collector is provided with a gas inlet, a gas outlet, a recoil port and a dust collecting component. A plurality of dust removal bags are arranged inside the bag dust collector. The industrial waste gas entering from the gas inlet is filtered by the dust removal bags and then flows out from the gas outlet.

[0009] A backwashing component, connected to the backwashing port of the bag filter, for backwashing the dust bag in a prescribed manner;

[0010] A first pipeline is connected to the gas outlet of the bag filter, and a variable frequency fan is provided on the first pipeline, and the variable frequency fan is used to generate negative pressure in the first pipeline;

[0011] A second pipeline is connected to the gas inlet of the bag filter, a pressure detection component is provided on the second pipeline, and is used to detect the pipeline pressure of the second pipeline. The second pipeline is connected to an air supply valve and a plurality of branches, and a cleaning valve is connected to the far end of each branch. A plurality of flap valves are connected to each branch, and each flap valve is provided with a sensor for detecting whether it is in an open or closed state;

[0012] A controller, electrically connected to the backwash component, the variable frequency fan, the pressure detection component, the air supply valve, and the sensor;

[0013] Wherein, the controller is configured to control the operating frequency of the variable frequency fan and the opening change of the air supply valve according to the number of flap valves opened and the change in the number, so that the negative pressure in the second pipeline is maintained at a preset pressure;

[0014] The controller includes a first control mode and a second control mode. When the opening number of the flap valve changes, the controller sequentially executes the first control mode and the second control mode. In the first control mode, the operating frequency F corresponding to the opening number of the flap valve is assigned to the variable frequency fan. 赋 , when the variable frequency fan reaches F 赋 After that, the second control mode is performed. In the second control mode, the difference between the negative pressure in the second pipeline and the preset negative pressure is compared. When the negative pressure in the second pipeline is lower than the preset value, the controller preferentially reduces the operating frequency of the variable frequency fan until the variable frequency fan is reduced to the preset frequency, and then increases the opening of the flap valve. When the negative pressure in the second pipeline is higher than the preset value, the controller preferentially reduces the opening of the flap valve until the flap valve is completely closed, and then increases the operating frequency of the variable frequency fan to make the negative pressure in the second pipeline at the preset value.

[0015] Preferably, the operating frequency F 赋 is related to the number of flap valves opened. When the number of flap valves opened is i, the controller controls the operating frequency of the variable frequency fan 1 to be F i+or F i- , where F i+ >F i- , i∈[0,N], N is a positive integer.

[0016] Preferably, when the opening number of the flap valve changes from i to i-1, in the first control mode, the controller controls the operating frequency of the variable frequency fan to be F (i-1)+ When the opening number of the flap valve changes from i to i+1, in the first control mode, the controller controls the operating frequency of the variable frequency fan 1 to be F (i+1)- .

[0017] Preferably, the flap valve farthest from the second pipeline on the same branch is defined as the distal flap valve, and the flap valve closest to the second pipeline on the same branch is defined as the proximal flap valve;

[0018] Control i remote flap valves to open at the same time, close the air supply valve, and adjust the operating frequency of the variable frequency fan to make the negative pressure of the second pipeline equal to the preset value, and obtain F i+ ;

[0019] Control i proximal flap valves to open at the same time, close the air supply valve, and adjust the operating frequency of the variable frequency fan to make the negative pressure of the second pipeline equal to the preset value, and obtain F i- .

[0020] Preferably, the controller monitors the opening number of the flap valve in real time. When the opening number of the flap valve is zero and the flap valve is not opened after a predetermined delay, the operating frequency of the variable frequency fan is reduced to put it in a standby or shutdown state. In the standby state, the negative pressure in the second pipeline becomes the standby negative pressure value. In the shutdown state, the variable frequency fan stops rotating.

[0021] Preferably, the controller is configured to sequentially open the cleaning valve at the far end of each branch at a predetermined time interval, and control the operating frequency of the variable frequency fan to adjust to the cleaning frequency to clean each branch.

[0022] Preferably, the bag filter is provided with a pressure difference detection component for detecting the pressure difference between the gas inlet and the gas outlet, and the controller is configured to backwash the dust bag according to a predetermined pressure difference and / or time interval.

[0023] Preferably, the controller is connected to a signal acquisition module, a mode determination module, a dust removal control module and a pressure regulation module;

[0024] The signal acquisition module is electrically connected to the sensor, the pressure detection component and the variable frequency fan, and is used to detect the switch state of each flap valve, the pressure of the second pipeline and the operating state of the variable frequency fan;

[0025] The mode judgment module controls the variable frequency fan to switch to a preset operating state according to the opening number of the flap valve and the closing time of the flap valve;

[0026] The dust removal control module is used to control the opening and closing states of the flap valve and the cleaning valve and the operating frequency of the variable frequency fan to perform negative pressure cleaning on each branch;

[0027] The pressure regulating module is used to adjust the frequency of the variable frequency fan and the opening of the air supply valve so that the negative pressure in the second pipeline is at a preset value.

[0028] The second aspect of the present invention proposes a technical solution, a cleaning and energy-saving control method for an industrial dust removal and exhaust system, using the above-mentioned cleaning and energy-saving control system for the industrial dust removal and exhaust system, including an energy-saving operation method and a cleaning method;

[0029] The energy-saving operation method comprises the following steps:

[0030] Step a1, continuously monitoring the opening state and opening quantity of each flap valve;

[0031] Step a2, according to the number of flap valves currently opened, controlling the operating frequency of the variable frequency fan to be at a preset value, and then adjusting the operating frequency of the variable frequency fan and the opening of the air supply valve according to the difference between the negative pressure in the second pipeline and the preset value, so that the negative pressure in the second pipeline is the same as the preset value;

[0032] Wherein, the cleaning method comprises the following steps:

[0033] Step b1, when the system is running, backwashing the dust removal bag according to a predetermined time interval and / or pressure difference;

[0034] Step b2: After the system is shut down, the cleaning valve at the far end of each branch is opened in sequence at a predetermined time interval, and the operating frequency of the variable frequency fan is controlled to be adjusted to the cleaning frequency to clean each branch.

[0035] Preferably, in step a2, when the opening number of the flap valve changes, a first control process and a second control process are included. In the first control process, the operating frequency F corresponding to the opening number of the flap valve is assigned to the variable frequency fan. 赋 , when the variable frequency fan reaches F 赋After that, a second control process is performed. In the second control process, the difference between the negative pressure in the second pipeline and the preset negative pressure is compared. When the negative pressure in the second pipeline is lower than the preset value, the controller preferentially reduces the operating frequency of the variable frequency fan until the variable frequency fan is reduced to the preset frequency, and then increases the opening of the flap valve. When the negative pressure in the second pipeline is higher than the preset value, the controller preferentially reduces the opening of the flap valve until the flap valve is completely closed, and then increases the operating frequency of the variable frequency fan to make the negative pressure in the second pipeline at the preset value.

[0036] Compared with the prior art, the advantages of the present invention are:

[0037] The control system proposed in this application sets different preset operating frequency parameters of the variable frequency fan according to the number of flap valves opened. When the variable frequency fan reaches the preset parameters, it automatically adjusts through the pressure difference. Through this pressure regulation method that combines parameter preset + PID regulation, the dust removal system can quickly match the corresponding air supply valve and fan frequency preset value during the startup process to cope with the changes in the terminal point position, reducing oscillation and overshoot. In addition, by linking the air supply valve with the fan frequency, the dust removal fan is prevented from increasing frequency and pressure when the air supply valve is opened to relieve pressure, that is, the dust removal fan is prevented from running at an unnecessary high frequency, achieving high efficiency and energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For clarity, not every component is labeled in every figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, in which:

[0039] Figure 1 It is a schematic diagram of the cleanliness and energy-saving control system of the industrial dust removal and exhaust system shown in this application;

[0040] Figure 2 It is a schematic diagram of each module of the controller shown in this application. DETAILED DESCRIPTION

[0041] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings.

[0042] In industrial dust removal systems, the switch status of each flap valve at the end of the system is determined by the user's usage status. When dust removal is required, the flap valve is opened manually or automatically, and the dust is discharged into the dust removal pipeline under the action of negative pressure. As the number of flap valves opened synchronously at the end changes, the demand for dust removal exhaust air volume changes, and then the negative pressure of the pipeline changes accordingly. If the aerodynamic performance of the dust removal fan cannot adapt to and follow this change, and quickly compensate or suppress the sharp increase or decrease in pipeline pressure, the dust at the dust collection point will escape or be over-absorbed, which will not achieve the expected dust removal effect, and the fan operating efficiency of the dust removal system will be reduced, resulting in increased system energy consumption.

[0043] [Cleanliness and energy-saving control system of industrial dust removal and exhaust system]

[0044] like Figure 1 As shown, the first aspect of the present invention proposes a clean and energy-saving control system for an industrial dust removal and exhaust system, including a bag dust collector 3, a backwash component 4, a first pipeline, a second pipeline 5 and a controller 102. With the bag dust collector 3 as the dividing line, the pipeline on the left side of the bag dust collector 3 is a negative pressure extraction pipeline, and the pipeline on the right side is a negative pressure pipeline. The end of the pipeline on the right side is a flap valve 6, and the flap valve 6 is set at the dust removal demand. Once the flap valve 6 is opened, negative pressure is generated at the place, which is used to adsorb dust at the place.

[0045] It should be understood that the bag filter 3 is provided with a gas inlet, a gas outlet, a recoil port and a dust collecting component. A plurality of dust bags are provided inside the bag filter 3. The industrial waste gas entering from the gas inlet is filtered by the dust bags and then flows out from the gas outlet.

[0046] In order to clean the dust bags, the backwash component 4 is connected to the backwash port of the bag-type dust collector 3 through the backwash pipe 41, and is used to backwash the dust bags in a prescribed manner. Backwashing is to reversely load high-pressure gas into the dust bags so that the dust on the surface is shaken off into the dust collecting device at the bottom of the bag-type dust collector 3. An ash discharge pump 33 is provided at the bottom of the bag-type dust collector 3. The ash discharge pump 33 is used to discharge the dust collected at the bottom of the bag-type dust collector 3 out of the bag-type dust collector 3.

[0047] Optionally, the bag filter 3 is provided with a pressure difference detection component 32 for detecting the pressure difference between the gas inlet and the gas outlet. When the pressure difference between the inlet and the gas outlet reaches a preset value, it indicates that the dust attached to the surface of the dust bag needs to be cleaned.

[0048] Optionally, the controller 102 is configured to backwash the dust removal bags according to a predetermined pressure difference and / or time interval.

[0049] In this way, through the combination of automatic sensing of dust bag pressure changes + fixed timing cycle, pulse backblowing is adopted to spray compressed air on individual bags one by one for high-pressure cleaning. During pulse backblowing, the pulse controller 31 is used to control the solenoid valve through pulse control, so that compressed air can be sprayed online to backblow the bags under negative pressure to remove dust.

[0050] like Figure 1 As shown, the first pipeline is connected to the gas outlet of the bag-type dust collector 3. A variable frequency fan 1 is provided on the first pipeline. The variable frequency fan 1 is used to generate negative pressure in the first pipeline. A high-efficiency H11 filter 2 is also provided between the variable frequency fan 1 and the bag-type dust collector 3, which can effectively capture particles with a diameter of 0.3 microns or more in the air and further filter and purify the air at the outlet of the dust collector.

[0051] like Figure 1 As shown, the second pipeline 5 is connected to the gas inlet of the bag filter 3, and a pressure detection component 51 is provided on the second pipeline 5 for detecting the pipeline pressure of the second pipeline 5. The second pipeline 5 is connected to an air supply valve 52 and a plurality of branches 53. The far end of each branch 53 is connected to a purge valve 54, and each branch 53 is connected to a plurality of flap valves 6. Each flap valve 6 is provided with a sensor for detecting whether it is in an open or closed state.

[0052] The pressure detection component 51 may be a pipeline pressure transmitter, which is used to detect the pressure of the main pipeline (second pipeline 5) of the dust removal and exhaust system as a basis for adjusting the variable frequency fan 1 and the air supply valve 52. The change in the number of flap valves 6 (end working points) opened at the same time will cause a sharp change in pipeline pressure.

[0053] Among them, the air supply valve 52 is arranged in the second pipeline 5. When the air supply valve 52 is opened, the negative pressure in the second pipeline 5 increases. Therefore, the air supply valve 52 is used for pipeline air supply and pressure relief, and is linked with the variable frequency fan 1 to control the pipeline pressure.

[0054] Furthermore, the controller 102 is electrically connected to the backwash component 4, the variable frequency fan 1, the pressure detection component 51, the air supply valve 52, and the sensor; the controller 102 is configured to control the operating frequency of the variable frequency fan 1 and the opening change of the air supply valve 52 according to the number of flap valves 6 opened and the change in the number, so that the negative pressure in the second pipeline 5 is maintained at a preset pressure.

[0055] The controller 102 includes a first control mode and a second control mode. When the number of flap valves 6 opened changes, the controller 102 sequentially executes the first control mode and the second control mode. In the first control mode, the variable frequency fan 1 is assigned a corresponding operating frequency F according to the number of flap valves 6 opened. 赋 , when the frequency conversion fan 1 reaches F 赋Then, the second control mode is performed. In the second control mode, the difference between the negative pressure in the second pipeline 5 and the preset negative pressure is compared. When the negative pressure in the second pipeline 5 is lower than the preset value, the controller 102 gives priority to reducing the operating frequency of the variable frequency fan 1 until the variable frequency fan 1 is reduced to the preset frequency, and then increases the opening of the flap valve 6. When the negative pressure in the second pipeline 5 is higher than the preset value, the controller 102 gives priority to reducing the opening of the flap valve 6 until the flap valve 6 is completely closed, and then increases the operating frequency of the variable frequency fan 1 to make the negative pressure in the second pipeline 5 at the preset value.

[0056] In this way, the controller 102 adopts a pressure regulation method that combines parameter preset + PID regulation. By presetting the applicable parameters of the air valve opening and the fan frequency in the combination mode of the opening and closing states of different numbers of flap valves 6, the dust removal system can quickly match the corresponding air valve and fan frequency preset values ​​during the startup process to cope with the changes in the number of terminal flap valves 6 opened, reduce oscillation and overshoot, and in addition, through the linkage between the air valve and the fan frequency, the dust removal fan can be prevented from increasing the frequency and pressure when the air valve is open to relieve pressure, that is, the dust removal fan can be prevented from running at an unnecessary high frequency, thereby achieving high efficiency and energy saving.

[0057] In an alternative embodiment, the operating frequency F 赋 The number of flap valves 6 that are opened is related to the number of flap valves 6 that are opened. When the number of flap valves 6 that are opened is i, the controller 102 controls the operating frequency of the variable frequency fan 1 to be F i+ or F i- , where F i+ >F i- , i∈[0,N], N is a positive integer, for example Figure 1 In the 1-8 flap valves 6 shown, the 8 flap valves 6 correspond to 16 preset operating frequencies, and each flap valve corresponds to two preset operating frequencies.

[0058] It should be understood that since a plurality of flap valves 6 are connected in one branch 53, and the opening and closing of the flap valves 6 at the proximal and distal ends have different effects on the negative pressure in the second pipeline 5, therefore, in order to more accurately assign a more precise preset operating frequency to the variable frequency fan 1, it is necessary to obtain the difference in operating frequency of the variable frequency fan 1 when the second pipeline 5 is at the target pressure, when the proximal flap valve 6 is opened and when the distal flap valve 6 is opened.

[0059] Further, the flap valve 6 farthest from the second pipeline 5 on the same branch 53 is defined as the distal flap valve, and the flap valve 6 closest to the second pipeline 5 on the same branch 53 is defined as the proximal flap valve;

[0060] Control i remote flap valves to open at the same time, close the air supply valve 52, and adjust the operating frequency of the variable frequency fan 1 so that the negative pressure of the second pipeline 5 is equal to the preset value, and obtain F i+ ;

[0061] Control i proximal flap valves to open at the same time, close the air supply valve 52, and adjust the operating frequency of the variable frequency fan 1 so that the negative pressure of the second pipeline 5 is equal to the preset value, and obtain F i- .

[0062] Thus, when the opening number of the flap valve 6 changes from i to i-1, in the first control mode, the controller 102 controls the operating frequency of the variable frequency fan 1 to be F (i-1)+ When the opening number of the flap valve 6 changes from i to i+1, in the first control mode, the controller 102 controls the operating frequency of the variable frequency fan 1 to be F (i+1)- .

[0063] In an optional embodiment, the number of flap valves 6 opened is changed from 3 to 2 as an example: the number of flap valves 6 is on a downward trend, which will cause the negative pressure of the pipeline to increase and the fan frequency needs to be reduced. Therefore, the preset value of opening the two flap valves 6 at the farthest ends at the same time, that is, F 2+ , and then the system switches back to PID precise adjustment (if the two flaps actually opened are not the farthest ends, the frequency will be further reduced during precise adjustment).

[0064] In another embodiment, the number of flap valves 6 opened changes from 1 to 2 as an example: the number of flap valves 6 is on an upward trend, which will cause the negative pressure in the pipeline to decrease, and the fan frequency needs to be increased. The preset value of opening the two flap valves at the nearest end at the same time, that is, F 2- Then switch back to PID precise adjustment (if the two flaps actually opened are not the closest ends, the frequency will be further increased during precise adjustment).

[0065] In this way, when the dust removal system is in working mode, once the number of flap valves 6 at the end that are opened changes, the control system matches the corresponding air supply valve and fan frequency preset values ​​to suppress and prevent large changes in pipeline pressure in a shorter time. After the pressure deviation is reduced to within the set deviation range or the feedback frequency of the fan is consistent with the set frequency, it switches back to PID regulation to stabilize the pressure.

[0066] Optionally, the above-mentioned set deviation range can be the set pressure value ±3000Pa.

[0067] In other embodiments, when half of the flap valves 6 are controlled to be open and the system is running stably, about 30% of the pressure deviation value caused by opening or closing one flap valve is used as the deviation setting value, and the setting deviation range is set to the set pressure value ± the deviation setting value.

[0068] Furthermore, in order to reduce the power consumption of the variable frequency fan 1, the controller 102 monitors the number of flap valves 6 opened in real time. When the number of flap valves 6 opened is zero and the flap valve 6 is not opened after a predetermined delay, the operating frequency of the variable frequency fan 1 is reduced to put it in a standby or shutdown state. In the standby state, the negative pressure in the second pipeline 5 becomes a standby negative pressure value. In the shutdown state, the variable frequency fan 1 stops rotating.

[0069] In this way, when the flap valve 6 is not online, the system's operating power consumption can be reduced by reducing the operating frequency or shutting down the system. It should be understood that when the system is in standby or shutdown state, once a corresponding number of flap valves 6 are opened in the system, the variable frequency fan 1 controls the operating frequency of the variable frequency fan 1 to reach the preset frequency according to the number of flap valves 6.

[0070] Furthermore, when the system stops after operation, the branch 53 needs to be cleaned, or when the system runs for a long time without stopping, the branch 53 should also be cleaned. Therefore, the cleaning can be carried out at a predetermined time interval or manually controlled.

[0071] Optionally, the controller 102 is configured to sequentially open the cleaning valve 54 at the far end of each branch 53 at a predetermined time interval, and control the operating frequency of the variable frequency fan 1 to adjust to the cleaning frequency to clean each branch 53 .

[0072] In this way, by cleaning one branch 53 in turn, the dust deposited in the branch 53 can be brought into the bag filter 3 by utilizing the higher pipeline negative pressure and flow rate.

[0073] In an optional embodiment, the controller 102 is connected to the signal acquisition module 103 , the mode determination module 104 , the dust removal control module 105 and the pressure regulation module 106 .

[0074] The signal acquisition module 103 is electrically connected to the sensor, the pressure detection component 51 and the variable frequency fan 1 , and is used to detect the switch state of each flap valve 6 , the pressure of the second pipeline 5 and the operating state of the variable frequency fan 1 .

[0075] The mode determination module 104 controls the variable frequency blower 1 to switch to a preset operating state according to the number of times the flap valve 6 is opened and the closing time of the flap valve 6 .

[0076] The mode determination module 104 can determine the operating mode of the system and the corresponding pressure setting value in each mode according to the collected opening position signal of the flap valve.

[0077] The controller 102 is also connected to the power collection module 107, which can be a smart meter that can read, store and archive system power consumption data (voltage, current, power consumption and other parameters) for energy-saving analysis.

[0078] In an optional embodiment, the system includes a working mode, a standby mode, a standby stop mode, a cleaning mode, and a stop mode.

[0079] Working mode: During the system startup process, when the signal acquisition module detects that the flap has an open position signal, it means that the end point is working online and the system has a need for dust removal and exhaust, then the system is judged to be in working mode. In working mode, the dust removal fan is turned on, and the working pressure setting value is used as the main pipeline target value.

[0080] Standby pressure mode: During system startup, if no open position signal is detected for the end flap, and there is still no open position signal after the delay time, the system is judged to be in standby mode. In standby mode, the dust removal fan is turned on, and the standby pressure setting value is used as the main pipeline target value.

[0081] Standby stop mode: During the system startup process, if the system is in standby mode and there is still no open position signal after the delay time, the system is judged to be in standby stop mode. In standby stop mode, the startup signal is maintained, and the variable frequency fan is turned off and no pressure adjustment is performed. In standby stop mode, once the terminal flap valve is detected to have an open position signal, it will enter the working mode again. In standby stop mode, the dust removal fan is turned off, and the power consumption of the system is greatly reduced.

[0082] Cleaning mode: When the system is manually shut down without any faults, or when the system is started up and the cycle cleaning or manual cleaning function is enabled, the system is in cleaning mode. In cleaning mode, the dust removal fan is turned on, and the cleaning pressure setting value is used as the main pipeline target value.

[0083] Stop mode: Manual stop or fault stop, the system is in stop mode.

[0084] The dust removal control module 105 is used to control the opening and closing states of the flap valve 6 and the cleaning valve 54 and the operating frequency of the variable frequency fan 1 to perform negative pressure cleaning on each branch 53 .

[0085] Among them, the dust removal control module 105 can perform judgment and processing of dust removal, cleaning, and dust unloading by controlling the pulse controller to spray compressed air flow to the bag filter for back-blowing dust removal, controlling the terminal cleaning valve to clean the pipeline, and controlling the opening of the dust unloading valve to remove dust online.

[0086] The pressure regulating module 106 is used to adjust the frequency of the variable frequency fan 1 and the opening of the air supply valve 52 so that the negative pressure in the second pipeline 5 is at a preset value.

[0087] It should be understood that the frequency increase of the variable frequency fan 1 increases the negative pressure in the pipeline. The increase in the opening of the air supply valve 52 reduces the negative pressure in the pipeline, that is, pressure relief. The frequency of the variable frequency fan 1 and the opening of the air supply valve 52 are linked. When the negative pressure in the pipeline is lower than the set target of the operation mode and the negative pressure needs to be increased, the air supply valve 52 is closed first, and then the frequency of the variable frequency fan 1 is increased after the air supply valve 52 is fully closed; when the negative pressure in the pipeline is higher than the set target of the operation mode and the negative pressure needs to be reduced, the frequency of the variable frequency fan 1 is reduced first, and then the opening of the air supply valve 52 is increased after the frequency is reduced to the lower limit frequency.

[0088] In this way, by linking the air supply valve with the fan frequency, the frequency conversion fan 1 is prevented from increasing frequency and pressure when the air supply valve 52 is opened to relieve pressure, that is, the frequency conversion fan 1 is prevented from running at an unnecessary high frequency, thereby achieving high efficiency and energy saving.

[0089] Furthermore, the controller 102 is also connected to the human-machine module 101. The human-machine module 101 collects the parameter status of the controller 102 through communication, and displays the operation screen, parameter settings, equipment operation and alarm status of the control system, which is conducive to user monitoring and manual intervention control.

[0090] [Cleanliness and energy-saving control methods for industrial dust removal and exhaust systems]

[0091] The second aspect of the present invention proposes a technical solution, a cleaning and energy-saving control method for an industrial dust removal and exhaust system, using the above-mentioned cleaning and energy-saving control system for the industrial dust removal and exhaust system, including an energy-saving operation method and a cleaning method;

[0092] The energy-saving operation method comprises the following steps:

[0093] Step a1, continuously monitoring the opening state and opening quantity of each flap valve 6;

[0094] Step a2, according to the current opening number of the flap valve 6, the operating frequency of the variable frequency fan 1 is controlled to be at a preset value, and then according to the difference between the negative pressure in the second pipeline 5 and the preset value, the operating frequency of the variable frequency fan 1 and the opening of the air supply valve 52 are adjusted to make the negative pressure in the second pipeline 5 the same as the preset value;

[0095] The cleaning method comprises the following steps:

[0096] Step b1, when the system is running, backwash the dust removal bags according to a predetermined time interval and / or pressure difference;

[0097] Step b2: After the system is shut down, the cleaning valve 54 at the far end of each branch 53 is opened in sequence at a predetermined time interval, and the operating frequency of the variable frequency fan 1 is controlled to be adjusted to the cleaning frequency to clean each branch 53.

[0098] Preferably, in step a2, when the opening number of the flap valve 6 changes, a first control process and a second control process are included. In the first control process, the operating frequency F corresponding to the opening number of the flap valve 6 is assigned to the variable frequency fan 1. 赋 , when the frequency conversion fan 1 reaches F 赋 After that, a second control process is performed. In the second control process, the difference between the negative pressure in the second pipeline 5 and the preset negative pressure is compared. When the negative pressure in the second pipeline 5 is lower than the preset value, the controller 102 gives priority to reducing the operating frequency of the variable frequency fan 1 until the variable frequency fan 1 is reduced to the preset frequency, and then increases the opening of the flap valve 6. When the negative pressure in the second pipeline 5 is higher than the preset value, the controller 102 gives priority to reducing the opening of the flap valve 6 until the flap valve 6 is completely closed, and then increases the operating frequency of the variable frequency fan 1 to make the negative pressure in the second pipeline 5 at the preset value.

[0099] In an optional embodiment, the dust removal control process includes dust removal, cleaning and dust unloading.

[0100] Dust removal: When the dust removal system is on, online pressure difference dust removal and online timed dust removal are combined.

[0101] Online timed dust removal is to start the pulse controller 31 to perform the timed dust removal and cleaning procedure according to the set timed cleaning sequence (the pulse controller 31 starts and stops according to the set opening time and closing time, and cycles according to the set number of times);

[0102] Online pressure differential cleaning means that when the pressure differential of the dust bag detected by the pressure differential detection component 32 is greater than the set cleaning pressure differential, the pulse controller 31 is started to perform dust cleaning through pulse control. When the pressure differential value of the dust bag is lower than the set cleaning stop pressure differential, the start signal of the pulse controller 31 is disconnected and cleaning is stopped.

[0103] Optionally, after the dust removal system is shut down and the dust removal fan stops, the control system starts the pulse controller according to the offline dust removal settings to perform a timed offline cleaning procedure (the pulse controller 31 starts and stops according to the set opening time and closing time, and cycles for a set number of times).

[0104] Cleaning: When the dust removal system is in cleaning mode, each cleaning valve 54 is opened / closed one by one according to the set opening time, switching time and number of cycles to enter the cleaning program, and the dust deposited in the pipeline branch is brought into the dust collector by using the higher pipeline negative pressure and flow rate.

[0105] Dust unloading: According to the material level detection in the waste bucket at the bottom of the dust collector, when the actual material level reaches the preset height, an alarm (sound and light alarm and high-brightness cycle prompt on the screen) will be issued to notify the system maintenance personnel to handle the dust, and at the same time close the ash unloading valve to stop the dust from falling into the waste bucket.

[0106] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A clean and energy-saving control system for an industrial dust removal and exhaust system, characterized in that: include: A bag dust collector (3) is provided with a gas inlet, a gas outlet, a recoil port and a dust collecting component. A plurality of dust removal bags are provided inside the bag dust collector (3). The industrial waste gas entering through the gas inlet is filtered by the dust removal bags and then flows out from the gas outlet. A backwashing component (4) connected to the backwashing port of the bag filter (3) and used for backwashing the dust bag in a prescribed manner; A first pipeline connected to the gas outlet of the bag filter (3), a variable frequency fan (1) being provided on the first pipeline, the variable frequency fan (1) being used to generate negative pressure in the first pipeline; a second pipeline (5) connected to the gas inlet of the bag filter (3); a pressure detection component (51) is provided on the second pipeline (5) for detecting the pipeline pressure of the second pipeline (5); the second pipeline (5) is connected to an air supply valve (52) and a plurality of branches (53); a cleaning valve (54) is connected to the far end of each branch (53); a plurality of flap valves (6) are connected to each branch (53); each flap valve (6) is provided with a sensor for detecting whether it is in an open or closed state; A controller (102) is electrically connected to the backwash component (4), the variable frequency fan (1), the pressure detection component (51), the air supply valve (52), and the sensor; The controller (102) is configured to control the operating frequency of the variable frequency fan (1) and the change in the opening degree of the air supply valve (52) according to the number of flap valves (6) opened and the change in the number, so that the negative pressure in the second pipeline (5) is maintained at a preset pressure; The controller (102) comprises a first control mode and a second control mode. When the opening number of the flap valve (6) changes, the controller (102) sequentially executes the first control mode and the second control mode. In the first control mode, an operating frequency F corresponding to the opening number of the flap valve (6) is assigned to the variable frequency fan (1). 赋 When the variable frequency fan (1) reaches F 赋 After that, a second control mode is performed. In the second control mode, the difference between the negative pressure in the second pipeline (5) and the preset negative pressure is compared. When the negative pressure in the second pipeline (5) is lower than the preset value, the controller (102) preferentially reduces the operating frequency of the variable frequency fan (1) until the variable frequency fan (1) is reduced to the preset frequency, and then increases the opening of the flap valve (6). When the negative pressure in the second pipeline (5) is higher than the preset value, the controller (102) preferentially reduces the opening of the flap valve (6) until the flap valve (6) is completely closed, and then increases the operating frequency of the variable frequency fan (1) so that the negative pressure in the second pipeline (5) is at the preset value.

2. The cleanliness and energy-saving control system of the industrial dust removal and exhaust system according to claim 1 is characterized in that: The operating frequency F 赋 is related to the number of times the flap valve (6) is opened. When the number of times the flap valve (6) is opened is i, the controller (102) controls the operating frequency of the variable frequency fan (1) to be F i+ or F i- , where F i+ >F i- , i∈[0,N], N is a positive integer.

3. The cleanliness and energy-saving control system of the industrial dust removal and exhaust system according to claim 2 is characterized in that: When the opening number of the flap valve (6) changes from i to i-1, in the first control mode, the controller (102) controls the operating frequency of the variable frequency fan (1) to be F (i-1)+ When the opening number of the flap valve (6) changes from i to i+1, in the first control mode, the controller (102) controls the operating frequency of the variable frequency fan (1) to be F (i+1)- .

4. The cleanliness and energy-saving control system of the industrial dust removal and exhaust system according to claim 2 is characterized in that: The flap valve (6) on the same branch (53) that is farthest from the second pipeline (5) is defined as a distal flap valve, and the flap valve (6) on the same branch (53) that is closest to the second pipeline (5) is defined as a proximal flap valve; i remote flap valves are controlled to open simultaneously, the air supply valve (52) is closed, and the operating frequency of the variable frequency fan (1) is adjusted so that the negative pressure of the second pipeline (5) is equal to a preset value, and F is obtained. i+ ; i proximal flap valves are controlled to open simultaneously, the air supply valve (52) is closed, and the operating frequency of the variable frequency fan (1) is adjusted so that the negative pressure of the second pipeline (5) is equal to a preset value, and F is obtained. i- .

5. The cleanliness and energy-saving control system of the industrial dust removal and exhaust system according to claim 1 is characterized in that: The controller (102) monitors the number of flap valves (6) opened in real time. When the number of flap valves (6) opened is zero, and the flap valve (6) is still not opened after a predetermined delay, the operating frequency of the variable frequency fan (1) is reduced to put it in a standby or shutdown state. In the standby state, the negative pressure in the second pipeline (5) becomes a standby negative pressure value. In the shutdown state, the variable frequency fan (1) stops rotating.

6. The cleanliness and energy-saving control system of the industrial dust removal and exhaust system according to claim 1 is characterized in that: The controller (102) is configured to sequentially open the cleaning valve (54) at the far end of each branch (53) at a predetermined time interval, and control the operating frequency of the variable frequency fan (1) to adjust to the cleaning frequency, so as to clean each branch (53).

7. The cleanliness and energy-saving control system of the industrial dust removal and exhaust system according to claim 1 is characterized in that: The bag filter (3) is provided with a pressure difference detection component for detecting the pressure difference between the gas inlet and the gas outlet, and the controller (102) is configured to backwash the dust removal bag according to a predetermined pressure difference and / or time interval.

8. The cleanliness and energy-saving control system of the industrial dust removal and exhaust system according to claim 1 is characterized in that: The controller (102) is connected to a signal acquisition module (103), a mode determination module (104), a dust removal control module (105) and a pressure regulation module (106); The signal acquisition module (103) is electrically connected to the sensor, the pressure detection component (51) and the variable frequency fan (1), and is used to detect the switch state of each flap valve (6), the pressure of the second pipeline (5) and the operating state of the variable frequency fan (1); The mode judgment module (104) controls the variable frequency fan (1) to switch to a preset operating state according to the number of times the flap valve (6) is opened and the closing time of the flap valve (6); The dust removal control module (105) is used to control the opening and closing states of the flap valve (6) and the cleaning valve (54) and the operating frequency of the variable frequency fan (1) to perform negative pressure cleaning on each branch (53); The pressure regulating module (106) is used to regulate the frequency of the variable frequency fan (1) and the opening of the air supply valve (52) so that the negative pressure in the second pipeline (5) is at a preset value.

9. A cleanliness and energy-saving control method for an industrial dust removal and exhaust system, characterized in that: A cleaning and energy-saving control system for an industrial dust removal and exhaust system using any one of claims 1 to 8, including an energy-saving operation method and a cleaning method; The energy-saving operation method comprises the following steps: Step a1, continuously monitoring the opening state and opening quantity of each flap valve (6); Step a2, according to the number of flap valves (6) currently opened, the operating frequency of the variable frequency fan (1) is controlled to be at a preset value, and then according to the difference between the negative pressure in the second pipeline (5) and the preset value, the operating frequency of the variable frequency fan (1) and the opening of the air supply valve (52) are adjusted so that the negative pressure in the second pipeline (5) is the same as the preset value; Wherein, the cleaning method comprises the following steps: Step b1, when the system is running, backwashing the dust removal bag according to a predetermined time interval and / or pressure difference; Step b2: After the system is shut down, the cleaning valve (54) at the far end of each branch (53) is opened in sequence at predetermined time intervals, and the operating frequency of the variable frequency fan (1) is controlled to be adjusted to the cleaning frequency to clean each branch (53).

10. The cleanliness and energy-saving control method of an industrial dust removal and exhaust system according to claim 9, characterized in that: In step a2, when the opening number of the flap valve (6) changes, a first control process and a second control process are included. In the first control process, the operating frequency F corresponding to the opening number of the flap valve (6) is assigned to the variable frequency fan (1). 赋 When the variable frequency fan (1) reaches F 赋 After that, a second control process is performed. In the second control process, the difference between the negative pressure in the second pipeline (5) and the preset negative pressure is compared. When the negative pressure in the second pipeline (5) is lower than the preset value, the controller (102) preferentially reduces the operating frequency of the variable frequency fan (1) until the variable frequency fan (1) is reduced to the preset frequency, and then increases the opening of the flap valve (6). When the negative pressure in the second pipeline (5) is higher than the preset value, the controller (102) preferentially reduces the opening of the flap valve (6) until the flap valve (6) is completely closed, and then increases the operating frequency of the variable frequency fan (1) so that the negative pressure in the second pipeline (5) is at the preset value.

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