CN115957473B - Multi-target multi-level control system for compressed air foam - Google Patents
Multi-target multi-level control system for compressed air foam Download PDFInfo
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- 239000006260 foam Substances 0.000 title claims abstract description 119
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 82
- 239000007788 liquid Substances 0.000 claims abstract description 44
- 238000011217 control strategy Methods 0.000 claims abstract description 19
- 230000005856 abnormality Effects 0.000 claims abstract description 4
- 230000002159 abnormal effect Effects 0.000 claims description 29
- 230000001105 regulatory effect Effects 0.000 claims description 18
- 238000006243 chemical reaction Methods 0.000 claims description 6
- 230000001276 controlling effect Effects 0.000 claims description 4
- 238000000034 method Methods 0.000 abstract description 11
- 230000008569 process Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 7
- 239000003795 chemical substances by application Substances 0.000 description 4
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005187 foaming Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
- Y02P90/02—Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
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Abstract
The invention discloses a compressed air foam multi-target multi-level control system which comprises a fire water flow control unit, a foam liquid mixing proportion control unit and a compressed air mixing proportion control unit. The fire water flow control unit adjusts the outlet flow of the system to adapt to the requirements of different tail end release devices; the foam liquid mixing proportion control unit adjusts the flow rate of the foam mixed liquid so as to maintain the optimal mixing proportion of the foam mixed liquid; the compressed air mixing proportion control unit adjusts the flow rate of compressed air to adjust different forms of foam. The control process is automatically completed by the system, so that the operation of operators is reduced to the maximum extent; according to the severity of the feedback abnormality of the system parameters, the control system executes control strategies with different priorities, and can realize automatic and rapid undisturbed switching, thereby improving the operation reliability of the system.
Description
Technical Field
The invention belongs to the technical field of fire-fighting equipment, and particularly relates to a compressed air foam control system.
Background
The compressed air foam system (Compressed Air Foam System, hereinafter called CAFS for short) is a novel fire extinguishing device with high efficiency and water saving. Compared with the traditional negative pressure foam fire extinguishing system, the CAFS can obviously reduce the tension between water molecules and increase the heat absorption area of a water film by injecting high-pressure compressed air into the foam mixed liquid to form high-energy-storage foam, thereby improving the fire extinguishing efficiency. Meanwhile, the compressed air foam has the characteristic of strong adhesive force, can continuously cool the surface of a burning object, plays a role in isolating air, reduces the possibility of reburning, and has a good isolating protection effect on unburned objects.
The optimal mixing ratio of the different kinds of foam extinguishing agents is different, taking the water film forming foam extinguishing agent AFFF as an example, 3% AFFF represents that the mixing ratio of the foam extinguishing agent to water is 3:97, and 6% AFFF represents that the mixing ratio of the foam extinguishing agent to water is 6:94. In addition, different types of fires have different requirements for foam morphology. Compressed air foam can be classified according to the degree of dryness and humidity: wet foam, medium foam (medium wet foam and medium dry foam), dry foam, respectively correspond to different fire scenarios. The wet foam has high water content, low foaming multiple and good permeability, and is commonly used for putting out B-type fires; the dry foam has the advantages of low water content, high foaming multiple, strong adhesive force and stability, and capability of being attached to the surface of an object for a long time, thereby playing a role in isolating air. The degree of dryness and wetness of the foam depends largely on the proportion of compressed air.
The fire scene is complex and various, and different demands are made on the flow and foam form. In the actual fire extinguishing process, the fire extinguishing system is required to continuously and stably output foam with qualified quality in the face of various abnormal working conditions. The existing compressed air foam system is designed aiming at a single scene, and the application range of the system is limited. The control method mostly adopts simple open-loop proportional control, and the mixing proportion precision is not high when the system flow is changed. In addition, the control strategy is relatively single, and serious maladjustment may occur when abnormality occurs in the system. Therefore, a control method of a compressed air foam system is needed, which can improve the applicability of the system to different flow demands, different types of foam liquid, different fire scenes and various abnormal working conditions, and enhance the stability and reliability of the fire extinguishing system.
Disclosure of Invention
In order to solve the technical problems mentioned in the background art, the invention provides a compressed air foam multi-target multi-level control system which can adapt to the demands of different tail end release devices on system flow, maintain the optimal mixing proportion of foam mixed liquid under different flow, flexibly adjust foam forms aiming at different types of fire scenes, improve the adaptability to various complex working conditions and improve the fire extinguishing effect.
In order to achieve the technical purpose, the technical scheme of the invention is as follows:
A compressed air foam multi-target multi-level control system comprises a fire water flow control unit, a foam liquid mixing proportion control unit and a compressed air mixing proportion control unit; the fire water flow control unit adjusts the system outlet flow to adapt to the requirements of different tail end release devices; the foam liquid mixing proportion control unit adjusts the flow rate of the foam mixed liquid so as to maintain the optimal mixing proportion of the foam mixed liquid; the compressed air mixing proportion control unit adjusts the compressed air flow rate to adjust different forms of foam; each control unit adopts a multi-level control strategy, and each control system executes the control strategies with different priorities according to the severity of the feedback abnormality of the system parameters.
Further, the fire-fighting water flow control unit comprises a fire-fighting water flow controller, a flow regulating valve and a fire-fighting water flow meter, wherein the flow regulating valve is arranged at the outlet of the fire-fighting water pump, and the opening of the flow regulating valve is changed to throttle the output of the fire-fighting water pump so as to control the flow of the outlet of the system; the fire-fighting water flow controller adopts a two-stage control strategy of flow closed loop and valve position open loop; when the system is normal, the system adopts flow closed-loop control preferentially, and takes the deviation delta Qw of the fire-fighting water flow target value Qw_set and the fire-fighting water flow meter output signal as an input signal of a fire-fighting water flow controller; when the fire water flow feedback is abnormal, automatically switching to valve position open-loop control; the fire water flow target value qw_set under the flow closed-loop control is set by a manual or upper control system according to the type of the tail end release device; and the fire water flow controller performs incremental PID calculation according to the deviation delta Qw to obtain a flow regulating valve opening target value vw_set.
Further, when the absolute value of the deviation Δqw is smaller than the dead zone fixed value qw_db, the incremental PID calculation is not performed, and the flow rate regulating valve opening target value vw_set is kept unchanged; and setting amplitude limiting control in the fire water flow controller, and outputting the valve opening degree by taking vw_low when vw_set calculated by the increment PID is lower than vw_low.
Further, the fire-fighting water flow controller carries out the abnormal auxiliary judgment of the fire-fighting water flow meter according to the real-time feedback of the fire-fighting water pressure, when the flow-pressure relationship seriously deviates from the characteristic curve of the water pump, the fire-fighting water flow controller judges that the fire-fighting water flow meter is abnormal, the locking increment PID is calculated at the moment, the closed-loop control of the flow is switched into the open-loop control of the valve, and the opening of the valve is directly set manually.
Further, the foam liquid mixing proportion control unit comprises a foam liquid mixing proportion controller, a servo motor, a plunger metering pump, a foam flowmeter and a rotating speed transmitter; the servo motor is connected with the piston in the working chamber of the foam pump through a worm, the rotary motion of the servo motor is converted into the reciprocating motion of the piston in the working chamber of the foam pump, and the motion frequency of the piston in the working chamber of the foam pump is changed by controlling the rotating speed of the servo motor, so that the flow rate of the foam pump outlet is changed; the servo controller, the servo motor, the plunger type metering pump and the rotating speed transmitter are integrally combined into actuators, the number of the actuators is 2, the 2 groups of actuators are mutually independent, and the foam liquid mixing proportion controller is respectively communicated with the 2 groups of actuators; the foam liquid mixing proportion controller adopts a three-level control strategy of flow closed loop, rotating speed closed loop and rotating speed open loop; the system is controlled by a flow closed loop preferentially when normal; when the foam flow feedback is abnormal, the control is automatically switched to the rotating speed closed-loop control; when foam flow feedback and servo motor rotating speed feedback are abnormal at the same time or fire water flow feedback is abnormal, automatically switching to rotating speed open-loop control; the foam liquid mixing proportion target value Fr_set under the flow closed-loop control and the total rotating speed target value Rset of the motor under the rotating speed open-loop control are set by a manual or upper control system according to the optimal mixing proportion requirements of different foam liquid types; and the foam liquid mixing proportion controller performs incremental PID calculation according to the deviation delta Qf of the foam flow target value and the actual value to obtain a total rotating speed target value Rset of the servo motor under rotating speed closed-loop control.
Further, dead zone control is set in the foam liquid mixing proportion controller, when the absolute value of the deviation delta Qf is smaller than the dead zone fixed value qf_db, incremental PID calculation is not executed, and the total rotating speed target value Rset of the servo motor is kept unchanged; when the foam flow feedback is abnormal, the foam flow actual value is obtained by multiplying the sum of the two servo motor rotating speed actual values by a flow-rotating speed conversion coefficient K1.
Further, under normal conditions, 2 sets of actuators are operated simultaneously, the rotating speed target value of each servo motor is half of the total rotating speed target value Rset/2 of the servo motor, when the system detects that one set of actuators has faults, a fault actuator loop is cut off, a single actuator mode is adopted, and the rotating speed target value of the single servo motor is equal to the total rotating speed target value Rset of the servo motor.
Further, the compressed air mixing proportion control unit comprises a compressed air mixing proportion controller, a screw air compressor and an air flowmeter;
when the screw air compressor is a variable frequency air compressor, the compressed air mixing proportion control unit further comprises a variable frequency controller, the compressed air mixing proportion controller adopts a flow closed loop, frequency closed loop and frequency open loop three-level control strategy, flow closed loop control is preferably adopted when the system is normal, the system is automatically switched to frequency closed loop control when air flow feedback is abnormal, and the system is automatically switched to frequency open loop control when air flow and frequency feedback are simultaneously abnormal or fire water flow feedback is abnormal;
When the screw air compressor is a power frequency air compressor, the compressed air mixing proportion control unit further comprises a bypass regulating valve, the compressed air mixing proportion controller adopts a flow closed-loop and bypass valve position open-loop two-stage control strategy, the system is controlled by a flow closed-loop preferentially when normal, and the control is automatically switched to the bypass valve position open-loop control when the air flow or fire water flow feedback is abnormal;
The compressed air mixing proportion target value Ar_set under the flow closed-loop control and the air compressor running frequency target value Fset/bypass valve opening Va_set under the open-loop control are set by a manual or superior control system according to the requirements of different fire scenes on foam forms; and the compressed air mixing proportion controller performs incremental PID calculation according to the deviation delta Qa of the compressed air flow target value and the actual value to obtain an air compressor operation frequency target value Fset/bypass valve opening Va_set under closed-loop control.
Further, dead zone control is provided in the compressed air mixing ratio controller, and when the absolute value of the deviation Δqa is smaller than the dead zone fixed value qa_db, the incremental PID calculation is not performed, and the air compressor operating frequency target value Fset/bypass valve opening va_set remains unchanged.
Further, when the air flow meter fails, the compressed air flow actual value is obtained by multiplying the air compressor operation frequency actual value by the flow-frequency conversion coefficient K2.
The beneficial effects brought by adopting the technical scheme are that:
According to the invention, through the closed-loop control strategy of the control unit, the multi-objective real-time accurate control of fire water flow, foam liquid mixing proportion, compressed air mixing proportion and the like is realized, and the applicability of the system to different flow demands, different types of foam liquids, different fire scenes and various abnormal working conditions is improved. Meanwhile, the invention provides a multi-level control method, which can be used for rapidly switching without disturbance when the components in the system are abnormal, so that abnormal shutdown and out-of-control of the system are avoided to the greatest extent, and the stability and reliability of the fire extinguishing system are enhanced.
Drawings
FIG. 1 is a schematic diagram of a compressed air foam multi-target multi-level control system according to the present invention;
FIG. 2 is a schematic diagram of the fire water flow control unit control of the present invention;
FIG. 3 is a schematic diagram of the control unit of the foam liquid mixing ratio control unit in the invention;
FIG. 4 is a schematic diagram of the variable frequency control of the compressed air mixing ratio control unit of the present invention;
fig. 5 is a schematic diagram of the industrial frequency control of the compressed air mixing ratio control unit of the present invention.
Detailed Description
The technical scheme of the present invention will be described in detail below with reference to the accompanying drawings.
As shown in fig. 1, the invention designs a compressed air foam multi-target multi-level control system which comprises a fire water flow control unit, a foam liquid mixing proportion control unit and a compressed air mixing proportion control unit.
The control principle diagram of the fire water flow control unit is shown in figure 2. The fire water flow control unit adopts a closed-loop throttling control strategy, the fire water pump generally adopts a power frequency operation mode, and the purpose of adjusting the flow is achieved by adjusting the opening of a flow adjusting valve arranged at the outlet of the fire water pump. The fire water flow rate adjusting method comprises the following steps:
1) The fire water flow target value qw_set is set by a manual or upper control system according to the type of the tail end release device;
2) The actual value Qw of the fire-fighting water flow is monitored and fed back in real time through an electromagnetic flowmeter, and the deviation delta Qw of the target value Qw_set and the actual value Qw is sent to a fire-fighting water flow controller;
3) The fire water flow controller calculates through an incremental PID method according to the deviation delta Qw to obtain a target value vw_set of the opening of the flow regulating valve, and converts the target value into a 4-20mA signal to be sent to the regulating valve, so that the opening of the regulating valve is controlled, and the fire water flow is changed;
4) In order to prevent flow fluctuation caused by too frequent regulating valve action, dead zone control is arranged in the fire water flow controller, when the absolute value of the deviation delta Qw is smaller than the dead zone fixed value Qw_db, incremental PID calculation is not performed, and the opening target value vw_set of the flow regulating valve is kept unchanged;
5) In order to prevent the operation pressure of the fire water pump from being higher than the applicable working condition due to the too small opening of the regulating valve, limiting control is arranged in the fire water flow controller, and when vw_set obtained by calculation of the increment PID is lower than vw_low, vw_low is used as the opening of the valve to be output;
6) The fire-fighting water flow controller carries out abnormal auxiliary judgment of the flow sensor according to the real-time feedback of the fire-fighting water pressure, when the flow-pressure relationship seriously deviates from the characteristic curve of the water pump, the controller judges that the flow sensor is abnormal, the locking increment PID calculation is switched from closed-loop control to open-loop control, and the valve opening is directly set manually.
The control schematic diagram of the foam liquid mixing proportion control unit is shown in fig. 3. The foam liquid mixing proportion control unit takes fire water flow as a reference value, adopts a multi-level control strategy of a flow control scheme, a rotating speed control scheme and an open-loop control scheme, and increases the running reliability of the system. The foam liquid mixing proportion adjusting method comprises the following steps:
1) The foam liquid mixing proportion target value Fr_set is set by a manual or superior control system according to the optimal mixing proportion requirements of different foam liquid types;
2) Dividing the actual fire-fighting water flow value Qw by (1-Fr_set) to obtain a total system flow target value, multiplying the total system flow target value by Fr_set to obtain a foam flow target value qf_set, and transmitting the deviation delta Qf of the qf_set and the actual value Qf to a foam liquid mixing proportion controller;
3) The foam liquid mixing proportion controller calculates through an incremental PID method according to the deviation delta Qf to obtain a target value Rset of the total rotating speed of the servo motor, converts the target value into a 4-20mA signal and distributes the 4-20mA signal to two servo controllers averagely, and changes the moving frequency of a piston in a working chamber of the foam pump by controlling the rotating speed of the servo motor so as to change the outlet flow of the foam pump;
4) In order to prevent flow fluctuation caused by too frequent change of the rotating speed of the servo motor, dead zone control is arranged in the foam liquid mixing proportion controller, when the absolute value of the deviation delta Qf is smaller than the dead zone fixed value qf_db, incremental PID calculation is not performed, and the rotating speed target value Rset of the servo motor is kept unchanged;
5) Under normal conditions, the two sets of actuators run simultaneously, and the rotating speed target value of each servo motor is half of the total rotating speed target value, namely Rset/2; when the system detects that one set of actuator fails, a failure actuator loop is cut off, and a single actuator mode is adopted, wherein the rotating speed target value of the servo motor is equal to the total rotating speed target value Rset;
6) Under normal conditions, the foam liquid mixing proportion control unit adopts a flow control scheme, and at the moment, the foam flow actual value Qf is obtained by an electromagnetic flowmeter; when the flowmeter fails, the feedback value can not correctly reflect the actual foam flow, at the moment, the control unit adopts a rotating speed control scheme, and the foam flow actual value Qf is obtained by multiplying the sum of rotating speed actual values of the two servo motors by a flow-rotating speed conversion coefficient K1;
7) When the foam flow target value qf_set is excessively large due to the fault of the fire water flowmeter or the foam flow feedback value Qf is excessively large due to the simultaneous fault of the foam flowmeter and the rotating speed transmitter, the control unit locks the increment PID calculation, the closed-loop control is switched to the open-loop control, and the rotating speed of the foam pump is directly set manually.
As shown in fig. 4 and 5, the compressed air mixing proportion control unit includes a variable frequency rotation speed control strategy and a power frequency bypass control strategy, which correspond to the situations that the variable frequency air compressor and the power frequency air compressor are configured in a system respectively. The air inflow of the compressed air is changed by adjusting the rotating speed of the motor or the opening of the bypass valve. The method for adjusting the mixing proportion of the compressed air comprises the following steps:
1) Setting a compressed air mixing proportion target value Ar_set by a manual or superior control system according to the requirements of different fire scenes on foam forms;
2) Multiplying the actual fire-fighting water flow value Qw by Ar_set to obtain a compressed air flow target value qa_set, and feeding the deviation delta Qa of the target value qa_set and the actual value Qa to a compressed air mixing proportion controller;
3) The compressed air mixing proportion controller calculates according to the deviation delta Qa by an incremental PID method to obtain an air compressor operating frequency target value Fset or a bypass valve opening Va_set, converts the target value into a 4-20mA signal, and changes the air inflow of compressed air by controlling the air compressor operating frequency or the bypass valve opening;
4) In order to prevent flow fluctuation caused by excessively frequent changes of the air compressor operating frequency or the bypass valve opening, dead zone control is set in the compressed air mixing proportion controller, when the absolute value of the deviation delta Qa is smaller than the dead zone fixed value qa_db, incremental PID calculation is not executed, and the air compressor operating frequency target value Fset or the bypass valve opening Va_set is kept unchanged;
5) When the system adopts a variable frequency air compressor, the compressed air mixing proportion control unit adopts a flow control scheme under normal conditions, and the compressed air flow actual value Qa is obtained by an air flowmeter; when the flowmeter fails, the feedback value cannot accurately reflect the actual air flow, and the control unit adopts a frequency control scheme, so that the compressed air flow actual value Qa is obtained by multiplying the air compressor running frequency actual value by a flow-frequency conversion coefficient K2;
6) When the deviation of the compressed air flow target value qa_set is overlarge due to the fault of the fire-fighting water flowmeter or the deviation of the compressed air flow feedback value Qa is overlarge due to the fault of the air flowmeter, the control unit locks the increment PID calculation, the closed-loop control is switched to the open-loop control, and the running frequency of the air compressor or the opening of the bypass valve chamber is directly set by manpower.
The embodiments are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited by the embodiments, and any modification made on the basis of the technical scheme according to the technical idea of the present invention falls within the protection scope of the present invention.
Claims (7)
1. A compressed air foam multi-target multi-level control system characterized by: the fire control system comprises a fire water flow control unit, a foam liquid mixing proportion control unit and a compressed air mixing proportion control unit; the fire water flow control unit adjusts the system outlet flow to adapt to the requirements of different tail end release devices; the foam liquid mixing proportion control unit adjusts the flow rate of the foam mixed liquid so as to maintain the optimal mixing proportion of the foam mixed liquid; the compressed air mixing proportion control unit adjusts the compressed air flow rate to adjust different forms of foam; each control unit adopts a multi-level control strategy, and each control system executes the control strategies with different priorities according to the severity of the feedback abnormality of the system parameters;
The fire-fighting water flow control unit comprises a fire-fighting water flow controller, a flow regulating valve and a fire-fighting water flowmeter, wherein the flow regulating valve is arranged at the outlet of the fire-fighting water pump, and the opening of the flow regulating valve is changed to throttle the output of the fire-fighting water pump so as to control the flow of the outlet of the system; the fire-fighting water flow controller adopts a two-stage control strategy of flow closed loop and valve position open loop; when the system is normal, the system adopts flow closed-loop control preferentially, and takes the deviation delta Qw of the fire-fighting water flow target value Qw_set and the fire-fighting water flow meter output signal as an input signal of a fire-fighting water flow controller; when the fire water flow feedback is abnormal, automatically switching to valve position open-loop control; the fire water flow target value qw_set under the flow closed-loop control is set by a manual or upper control system according to the type of the tail end release device; the fire water flow controller performs incremental PID calculation according to the deviation delta Qw to obtain a flow regulating valve opening target value vw_set;
The foam liquid mixing proportion control unit comprises a foam liquid mixing proportion controller, a servo motor, a plunger metering pump, a foam flowmeter and a rotating speed transmitter; the servo motor is connected with the piston in the working chamber of the foam pump through a worm, the rotary motion of the servo motor is converted into the reciprocating motion of the piston in the working chamber of the foam pump, and the motion frequency of the piston in the working chamber of the foam pump is changed by controlling the rotating speed of the servo motor, so that the flow rate of the foam pump outlet is changed; the servo controller, the servo motor, the plunger type metering pump and the rotating speed transmitter are integrally combined into actuators, the number of the actuators is 2, the 2 groups of actuators are mutually independent, and the foam liquid mixing proportion controller is respectively communicated with the 2 groups of actuators; the foam liquid mixing proportion controller adopts a three-level control strategy of flow closed loop, rotating speed closed loop and rotating speed open loop; the system is controlled by a flow closed loop preferentially when normal; when the foam flow feedback is abnormal, the control is automatically switched to the rotating speed closed-loop control; when foam flow feedback and servo motor rotating speed feedback are abnormal at the same time or fire water flow feedback is abnormal, automatically switching to rotating speed open-loop control; the foam liquid mixing proportion target value Fr_set under the flow closed-loop control and the total rotating speed target value Rset of the motor under the rotating speed open-loop control are set by a manual or upper control system according to the optimal mixing proportion requirements of different foam liquid types; the foam liquid mixing proportion controller performs incremental PID calculation according to the deviation delta Qf of the foam flow target value and the actual value to obtain a total rotating speed target value Rset of the servo motor under rotating speed closed-loop control;
the compressed air mixing proportion control unit comprises a compressed air mixing proportion controller, a screw air compressor and an air flowmeter;
when the screw air compressor is a variable frequency air compressor, the compressed air mixing proportion control unit further comprises a variable frequency controller, the compressed air mixing proportion controller adopts a flow closed loop, frequency closed loop and frequency open loop three-level control strategy, flow closed loop control is preferably adopted when the system is normal, the system is automatically switched to frequency closed loop control when air flow feedback is abnormal, and the system is automatically switched to frequency open loop control when air flow and frequency feedback are simultaneously abnormal or fire water flow feedback is abnormal;
When the screw air compressor is a power frequency air compressor, the compressed air mixing proportion control unit further comprises a bypass regulating valve, the compressed air mixing proportion controller adopts a flow closed-loop and bypass valve position open-loop two-stage control strategy, the system is controlled by a flow closed-loop preferentially when normal, and the control is automatically switched to the bypass valve position open-loop control when the air flow or fire water flow feedback is abnormal;
The compressed air mixing proportion target value Ar_set under the flow closed-loop control and the air compressor running frequency target value Fset/bypass valve opening Va_set under the open-loop control are set by a manual or superior control system according to the requirements of different fire scenes on foam forms; and the compressed air mixing proportion controller performs incremental PID calculation according to the deviation delta Qa of the compressed air flow target value and the actual value to obtain an air compressor operation frequency target value Fset/bypass valve opening Va_set under closed-loop control.
2. The compressed air foam multi-target multi-level control system of claim 1, wherein: when the absolute value of the deviation Δqw is smaller than the dead zone fixed value qw_db, the incremental PID calculation is not performed, and the flow regulating valve opening target value vw_set remains unchanged; and setting amplitude limiting control in the fire water flow controller, and outputting the valve opening degree by taking vw_low when vw_set calculated by the increment PID is lower than vw_low.
3. The compressed air foam multi-target multi-level control system of claim 1, wherein: the fire-fighting water flow controller carries out the abnormal auxiliary judgment of the fire-fighting water flow meter according to the real-time feedback of the fire-fighting water pressure, when the flow-pressure relationship seriously deviates from the characteristic curve of the water pump, the fire-fighting water flow controller judges that the fire-fighting water flow meter is abnormal, the locking increment PID is calculated at the moment, the closed-loop control of the flow is switched into the open-loop control of the valve, and the opening of the valve is directly set manually.
4. The compressed air foam multi-target multi-level control system of claim 1, wherein: setting dead zone control in the foam liquid mixing proportion controller, and when the absolute value of the deviation delta Qf is smaller than the dead zone fixed value qf_db, not executing incremental PID calculation, and keeping the total rotating speed target value Rset of the servo motor unchanged; when the foam flow feedback is abnormal, the foam flow actual value is obtained by multiplying the sum of the two servo motor rotating speed actual values by a flow-rotating speed conversion coefficient K1.
5. The compressed air foam multi-target multi-level control system of claim 1, wherein: under normal conditions, 2 sets of actuators run simultaneously, the rotating speed target value of each servo motor is half of the total rotating speed target value Rset/2 of the servo motors, when a system detects that one set of actuators has faults, a fault actuator loop is cut off, a single actuator mode is adopted, and the rotating speed target value of each servo motor is equal to the total rotating speed target value Rset of the servo motor.
6. The compressed air foam multi-target multi-level control system of claim 1, wherein: the dead zone control is set in the compressed air mixing ratio controller, and when the absolute value of the deviation Δqa is smaller than the dead zone fixed value qa_db, the incremental PID calculation is not performed, and the air compressor operation frequency target value Fset/bypass valve opening va_set remains unchanged.
7. The compressed air foam multi-target multi-level control system of claim 1, wherein: when the air flow meter fails, the actual value of the compressed air flow is obtained by multiplying the actual value of the operating frequency of the air compressor by the flow-frequency conversion coefficient K2.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101543668A (en) * | 2009-03-05 | 2009-09-30 | 公安部上海消防研究所 | An automatic foam proportional mixing digital display controlling module |
| CN104524717A (en) * | 2014-12-24 | 2015-04-22 | 无锡五洋赛德压缩机有限公司 | Foam fire-extinguishing device with internal screw type air compressor |
| CN109513140A (en) * | 2018-12-06 | 2019-03-26 | 陕西航天动力高科技股份有限公司 | A kind of control method of fixed B class A foam A extinguishing device and extinguishing device |
| KR102200119B1 (en) * | 2020-07-15 | 2021-01-08 | 신정개발특장차 주식회사 | Compressed air foam system |
| CN113359416A (en) * | 2021-06-11 | 2021-09-07 | 西安理工大学 | Multi-input single-output compressed air foam system based on PLC and control method |
-
2021
- 2021-10-09 CN CN202111176764.2A patent/CN115957473B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101543668A (en) * | 2009-03-05 | 2009-09-30 | 公安部上海消防研究所 | An automatic foam proportional mixing digital display controlling module |
| CN104524717A (en) * | 2014-12-24 | 2015-04-22 | 无锡五洋赛德压缩机有限公司 | Foam fire-extinguishing device with internal screw type air compressor |
| CN109513140A (en) * | 2018-12-06 | 2019-03-26 | 陕西航天动力高科技股份有限公司 | A kind of control method of fixed B class A foam A extinguishing device and extinguishing device |
| KR102200119B1 (en) * | 2020-07-15 | 2021-01-08 | 신정개발특장차 주식회사 | Compressed air foam system |
| CN113359416A (en) * | 2021-06-11 | 2021-09-07 | 西安理工大学 | Multi-input single-output compressed air foam system based on PLC and control method |
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