CN115645802A - Integrated compressed air foam fire extinguishing system and control method thereof - Google Patents
Integrated compressed air foam fire extinguishing system and control method thereof Download PDFInfo
- Publication number
- CN115645802A CN115645802A CN202211340345.2A CN202211340345A CN115645802A CN 115645802 A CN115645802 A CN 115645802A CN 202211340345 A CN202211340345 A CN 202211340345A CN 115645802 A CN115645802 A CN 115645802A
- Authority
- CN
- China
- Prior art keywords
- foam
- air
- flow
- water
- path
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Flow Control (AREA)
Abstract
The invention discloses an integrated compressed air foam fire extinguishing system and a control method thereof, wherein the integrated compressed air foam fire extinguishing system comprises a control center, a foam generator, three input units and a power supply module; the three input units comprise a foam solution input unit, a waterway input unit and an air channel input unit; the standby air path input unit is used as a backup of the air path input unit; the control center controls the flow of the three input units to mix the compressed air, the foam stock solution and the water in the foam generator to generate compressed air foam, and then the compressed air foam is output. The invention provides the control method of the system, so that the compressed air fire extinguishing system can run more stably and reliably, and the system has certain practical significance.
Description
Technical Field
The invention belongs to the technical field of industrial automatic fire fighting, and particularly relates to an integrated compressed air foam fire extinguishing system and a control method of the system.
Background
A Compressed Air Foam System (CAFS) is a new type of fire extinguishing System that has been developed relatively rapidly in recent years abroad, and because of its high fire extinguishing efficiency, it is widely used to extinguish various types of fires. However, the traditional CAFS is formed by combining a plurality of modules, so that the low integration level causes large floor area and high cost; in addition, the foaming principle in the compressed air foam fire extinguishing system and the dynamic control of equipment are the core of the whole system, how to quickly and stably generate foam meeting fire extinguishing requirements becomes a difficulty in system development at present, the design of CAFS equipment controllers is less researched, although some basic PID controllers aiming at CAFS equipment are proposed at present, the problem that various working conditions cannot be flexibly faced exists, foam paths and air paths are basically adjusted, water paths are not adjusted, however, the dynamic stability of the whole system can be affected by the size of water flow, and therefore the design of the PID controllers of the water paths is also important.
Disclosure of Invention
The invention aims to provide an integrated compressed air foam fire extinguishing system and a control method thereof, and solves the problems that the existing CAFS equipment has flexible adaptability to various working conditions and needs to be further optimized in terms of adjustment of a water path.
The invention adopts a technical scheme that;
an integrated compressed air foam fire extinguishing system comprises a control center for controlling the whole system, a power supply, an air circuit, a water circuit, a foam circuit and a standby air compressor arranged outside;
an air compressor of the air channel is connected to the foam generator through an air channel, and the air channel is provided with a one-way valve and a pressure regulating valve; the foam path is provided with a foam pump and is connected to a first passage of the three-way ball valve through a foam pipeline; the water passage is connected to a second passage of the three-way ball valve through a water pipeline, and the water pipeline is provided with a variable frequency centrifugal pump and a water flowmeter; the third tee of the tee-joint ball valve is connected to the foam generator through a mixing pipe; mixing water and foam liquid in a mixing pipe to form mixed liquid; a pressure sensor is arranged at the front end of the foam generator, the mixed liquid and air are mixed in the foam generator to form a compressed air foam solution, and the compressed air foam solution is output through an electric butterfly valve; the backup air compressor is used as a backup and is connected to the air line via a check valve.
The other technical scheme of the invention is that;
the control method of the system specifically comprises the following steps:
and 4, obtaining the given air pressure through conversion after the air flow is determined, and adjusting the constancy of the air pressure of the air path by using a PID controller in the air path, wherein in the process, after error signals are generated by comparing the actual output air pressure with the given input air pressure through a comparison link, the error signals are used as the input of the PID controller, the output of the PID controller controls a one-way valve, the output quantity of the system is compared with the input of the system through a transfer function of a proportional valve and a flow limiting characteristic K3 of the one-way valve, and the gas phase pressure is automatically adjusted to maintain the constancy of the pressure.
The invention is also characterized in that;
in step 1, the flow index of the output compressed air foam is according to the foam mixing ratio R FW The method is characterized in that the foam flow and the water flow are mixed according to the properties of the foam stock solution, namely 1%, 3% and 6%, and the like, so that the PID control algorithm for determining the water flow in the water channel is specifically shown in the following formula (1):
in step 2, the foam path PID algorithm is specifically as follows:
according to the foam mixing ratio R FW The foam flow and the water flow are divided into 1 percent, 3 percent and 6 percent according to the property of the foam stock solution and mixed according to the following formulas (2) and (3):
wherein Q is F For the flow of foam, Q W Is the water flow.
In step 4, the air path PID algorithm is specifically as follows:
according to gas-liquid ratio R AH Mixing air with a gas-liquid ratio of 4, 1 or 3, 1 or 6 with foam mixed liquid to generate foam quality required by fire extinguishing, wherein the PID algorithm of an air channel can be obtained according to the requirements of fire extinguishing as follows:
wherein the gas-liquid ratio R AH Is the ratio of the gas flow to the liquid flow, Q A Is the air flow rate, Q H The flow rate of the foam stock solution and the water are superposed, and the gas-liquid ratio R AH I.e. the air flow rate Q A And the flow rate Q of the mixed liquid H The ratio of (a) to (b);
the ratio of the pressure detected by the air path pressure sensor and the mixing chamber pressure sensor is as follows:
P A ＝KP H (5)；
wherein, P A Is the air pressure, P H Is the post-mixing pressure of the water and the foaming solution;
from the above, it follows that the gas-liquid ratio can be adjusted by adjusting the value K, wherein:
1.0≤K≤1.15(6)；
by utilizing the relation, the air and the foam mixed liquid can be fully mixed, so that compressed air foam suitable for various fire scenes can be generated by changing the K value.
Compared with the prior art, the integrated compressed air foam fire extinguishing system and the control method thereof have the advantages that the air compressor, the foam pump, the water pump and the control and power supply module are integrated together, the size is reduced to a certain extent, the cost is saved, the reliability of the system operation is greatly improved, and meanwhile, a standby port is reserved outside the equipment and can be accessed by an external air compressor to improve the input capacity of the system; in addition, the adopted control method is novel PQ control in a multi-PI regulation mode, and the control of a water path is added on the basis that the existing control algorithms only regulate a foam path and an air path, so that under the condition that three PID controllers regulate together, the system outputs more accurately and completely meets the requirement of fire extinguishing.
Drawings
FIG. 1 is a system block diagram of an integrated compressed air foam fire suppression system of the present invention;
FIG. 2 is a functional block diagram of a water circuit PID in an integrated compressed air foam fire suppression system of the present invention;
FIG. 3 is a schematic block diagram of a foam circuit PID in an integrated compressed air foam fire suppression system of the present invention;
FIG. 4 is a schematic block diagram of an air circuit PID in an integrated compressed air foam fire extinguishing system
FIG. 5 is a block diagram of the control logic for a PID in an integrated compressed air foam fire suppression system of the present invention.
In the figure, 1, a water injection port, 2, a foam liquid injection port, 3, a compressed air foam liquid output port, 4, a variable frequency centrifugal pump, 5, a foam pump, 6, a three-way ball valve, 7, a pressure sensor, 8, an electric butterfly valve, 9, a pressure regulating valve, 10, a one-way valve, 11, an air compressor, 12, a control center, 13, a power supply, 14, a foam generator, 15, a water flowmeter and 16, a standby air compressor are arranged.
Detailed Description
An integrated compressed air foam fire suppression system and a control method thereof according to the present invention will be described in detail with reference to the accompanying drawings and embodiments.
The invention discloses an integrated compressed air foam fire extinguishing system, which comprises a foam generator, a power supply, an air compressor, a foam pump, a variable frequency centrifugal pump, a control center, a pressure sensor, a variety of valves and pipelines, wherein the foam generator is connected with the power supply; an air compressor 11 of an air path is connected with a foam generator 14 through a pressure regulating valve 9 and a one-way valve 10, a waterway pipeline is connected to one end of a three-way ball valve 6 through a variable frequency centrifugal pump 4, the other end of the three-way ball valve is connected with a foam pump 5, the two are mixed in the pipeline and then are also connected into the foam generator 14 through the pipeline, a water flow meter 15 is connected into the waterway and used for detecting the water flow, a pressure sensor 7 is arranged at the front end of the foam generator to detect the pressure of the mixed liquid, the three are finally mixed in the foam generator 14 to form compressed air foam solution which is output through an electric butterfly valve 8, and meanwhile, an external standby air compressor 16 is connected into the foam generator through the one-way valve 10 to be used for standby.
As shown in FIG. 2, the relevant processes for the control center control algorithm of the present system; the first step is as follows: obtaining water flow according to a CAFS (computer aided design) flow standard, wherein a quantitative relation exists between the water flow and the foam solution flow, so that the foam solution flow can be obtained, and meanwhile, the air flow can be obtained according to a gas-liquid ratio; the second step: when the foam channel of the air channel is adjusted, the water flow in the water channel is in dynamic change due to the fact that the air flow and the foam flow are also in dynamic change, the water flow measured by the water flow meter is compared with a set value, the obtained difference value is sent to the water channel PID controller, and then the variable frequency centrifugal pump in the water channel is adjusted to achieve the purpose that the water flow can be adjusted to achieve the set target.
As shown in fig. 3, after the water flow rate is calculated according to the flow rate index, the actual foam liquid flow rate output by the foam circuit is compared with the expected foam liquid flow rate according to the quantitative relation between the water flow rate and the foam solution flow rate, the obtained difference is sent to the PID controller of the foam liquid circuit, the foam pump is adjusted through the output of the PID controller, and the output error of the foam liquid is reduced to reach the expected index.
As shown in fig. 4, the conversion relationship between the air flow and the air pressure can be obtained through the characteristics of the check valve, and the air pressure and the pressure of the mixed liquid also have a certain algorithm relationship, so that the actually obtained air pressure is compared with a preset value, the obtained difference value is used as the input of an air channel PID controller, and then the proportional valve and the check valve are controlled through the output of the PID controller, and the air pressure is adjusted to reach the expected set target.
As shown in fig. 5, the normal operation mode of the control flow includes: starting an air path, a water path and an output channel, namely starting an air compressor, a centrifugal pump and an outlet valve, and starting a foam path according to a three-section type operation mode, namely detecting whether residual foam liquid exists through a tuning fork sensor, then starting the foam pump, setting a three-way ball valve and conducting the foam path; secondly, calculating the flow of the foam liquid on the one hand after measuring the water flow by the waterway water flow meter, converting the calculated flow of the foam liquid into an analog quantity and sending the analog quantity to a servo motor, executing by the servo motor to send out a foam stock solution to obtain an operation instruction, detecting whether the target foam quantity is reached by a foam flow detector of a foam path, and returning to calculate the flow of the foam solution again if the target foam quantity is not reached; the third step: when the foam loop unit executes, converting water flow detected by the water flow meter into analog quantity and sending the analog quantity to the variable-frequency centrifugal pump, adjusting the water flow by adjusting the rotating speed of the pump, detecting whether the water flow reaches the standard through the water flow meter, and if the water flow does not reach the standard, returning to recalculate the water flow; the fourth step: after the water path and the foam path are mixed, the pressure of the water solution is measured by a pressure sensor, the corresponding required air pressure is calculated, the required air pressure is converted into analog quantity to be sent to an electric proportional valve to adjust a pressure reducing valve to control the air pressure of the whole loop, and finally, whether the air pressure reaches a target value is detected by a pressure transmitter, and if the air pressure does not reach the target value, the required air pressure is returned to be continuously calculated; the fifth step: if the algorithm execution of the three units of the air path, the water path and the foam path is correct and meets the target setting, the fire alarm is judged, if the alarm is relieved, the three-way ball valve is set again to close the foam path and the water path, then the foam pump, the air compressor and the centrifugal pump are closed, finally the outlet valve is closed to finish the operation of the equipment, and if the fire alarm is not relieved, the operation is continued by returning to the second step.
The invention relates to an integrated compressed air foam fire extinguishing system and a control method thereof, wherein the integrated compressed air foam fire extinguishing system is characterized in that the control method comprises the following steps of (1) according to the air flow and the pressure of the foam fire extinguishing system; flow rate and pressure of the foam stock solution; the mutual influence relation of water flow and pressure provides a novel control method, so that the compressed air fire extinguishing system can run more stably and reliably, and has certain practical significance.
Claims (5)
1. An integrated compressed air foam fire extinguishing system is characterized by comprising a control center (12) for controlling the whole system, a power supply (13), an air path, a water path, a foam path and a standby air compressor (16) arranged outside;
an air compressor (11) of the air path is connected to a foam generator (14) through an air path, and the air path is provided with a one-way valve (10) and a pressure regulating valve (9); the foam path is provided with a foam pump (5) and is connected to a first passage of a three-way ball valve (6) through a foam pipeline; the water channel is connected to a second passage of the three-way ball valve (6) through a water pipeline, and the water pipeline is provided with a frequency centrifugal pump (4) and a water flowmeter (15); a third tee of the three-way ball valve (6) is connected to a foam generator (14) through a mixing pipe; mixing water and foam liquid in a mixing pipe to form mixed liquid; a pressure sensor (7) is arranged at the front end of the foam generator (14), the mixed liquid and air are mixed in the foam generator (14) to form a compressed air foam solution, and the compressed air foam solution is output through an electric butterfly valve (8); the standby air compressor (16) is used as a standby and is connected to the air pipeline through a one-way valve (10).
2. An integrated compressed air foam fire suppression system according to claim 1, wherein the method of controlling the system comprises the steps of:
step 1, firstly, determining the water flow, wherein a first-order inertia link relation exists between the water flow and the foam flow, and the flow of the foam solution can be determined after the water flow is determined; after the water flow is determined, the variable-frequency centrifugal pump starts to work, the water flowmeter starts to detect the water flow, wherein a PID controller is arranged in the water channel, the measured output water flow is compared with the given water flow through a water pump transfer function K1, the obtained error signal is used as the input of the PID controller, and then the PID controller of the water channel is used for adjusting the variable-frequency centrifugal pump in the water channel to change the water flow so as to keep the water flow and the pressure constant under the condition of a fixed gas-liquid ratio;
step 2, after the water flow meter detects the change of water flow, the foam pump starts to work, the foam solution is conveyed into the foam path according to the set foam output flow index of compressed air, the control of the flow of the foam solution is realized through a PID (proportion integration differentiation) controller of the foam path, the actual output flow of the foam path is compared with the given foam solution flow after passing through a foam pump transfer function K2, the difference value of the actual output flow of the foam path and the given foam solution flow is used as the input of the PID controller, the output of the PID controller controls the foam pump, and the flow of the foam solution is automatically adjusted, so that the output quantity of the foam path is maintained unchanged;
step 3, while carrying out steps 1 and 2, mixing the foam solution and the waterway through the pipeline before entering the mixing chamber, obtaining the pressure of the mixed solution through a pressure sensor according to the characteristics of the infusion pipeline, calculating the given air flow according to the set gas-liquid ratio, converting the calculated air flow into the air pressure through the characteristics of the one-way valve, and determining the relationship among the foam solution, the water and the air through the characteristics of the pipeline, the characteristics of the one-way valve and the gas-liquid ratio, wherein the first-order inertia link relationship also exists between the air pressure and the pressure of the mixed solution;
step 4, obtaining the given air pressure through conversion after determining the air flow, and adjusting the constancy of the air pressure of the air path by using a PID controller in the air path, wherein in the process, after an error signal is generated by comparing the actual output air pressure with the given input air pressure through a comparison link, the error signal is used as the input of the PID controller, the output of the PID controller controls a one-way valve, the output quantity of the system is compared with the input of the system through a transfer function of a proportional valve and a flow limiting characteristic K3 of the one-way valve, and the gas phase pressure is automatically adjusted to maintain the constancy of the pressure.
3. An integrated compressed air foam fire suppression system according to claim 1, wherein in step 1, the flow indicator of the outgoing compressed air foam is based on the foam mix ratio R FW The proportion of the foam flow and the water flow is divided into 1%, 3% and 6% according to the nature of the foam stock solution, and the PID control algorithm for determining the water flow in the water channel is specifically shown in the following formula (1):
4. an integrated compressed air foam fire suppression system according to claim 1, wherein in step 2, the foam path PID algorithm is as follows:
according to the foam mixing ratio R FW Mixing the foam flow and the water flow according to the proportion of 1%, 3% and 6% of the foam stock solution according to the following formulas (2) and (3):
wherein Q is F For the flow of foam, Q W Is the water flow.
5. An integrated compressed air foam fire extinguishing system according to claim 1, wherein in step 4, the air circuit PID algorithm is as follows:
according to gas-liquid ratio R AH Mixing air with a gas-liquid ratio of 4, 1 or 3, 1 or 6 with foam mixed liquid to generate foam quality required for fire extinguishing, wherein the PID algorithm of an air path can be obtained as follows according to the fire extinguishing requirement:
wherein the gas-liquid ratio R AH Is the ratio of the gas flow rate to the liquid flow rate, Q A Is the air flow rate, Q H The flow rate of the foam stock solution and the water are superposed, and the gas-liquid ratio R AH I.e. the air flow rate Q A And the flow rate Q of the mixed liquid H The ratio of (A) to (B);
the ratio of the pressure detected by the air path pressure sensor and the mixing chamber pressure sensor is as follows:
P A ＝KP H (5)；
wherein, P A Is the air pressure, P H Is the post-mixing pressure of the water and the foaming solution;
adjusting the gas-liquid ratio by adjusting the value of K, wherein:
1.0≤K≤1.15(6)；
by utilizing the relation, the air and the foam mixed liquid can be fully mixed, so that compressed air foam suitable for various fire scenes can be generated by changing the K value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211340345.2A CN115645802A (en) | 2022-10-28 | 2022-10-28 | Integrated compressed air foam fire extinguishing system and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211340345.2A CN115645802A (en) | 2022-10-28 | 2022-10-28 | Integrated compressed air foam fire extinguishing system and control method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115645802A true CN115645802A (en) | 2023-01-31 |
Family
ID=84994014
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211340345.2A Pending CN115645802A (en) | 2022-10-28 | 2022-10-28 | Integrated compressed air foam fire extinguishing system and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115645802A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117873216A (en) * | 2024-02-01 | 2024-04-12 | 江苏拓米洛高端装备股份有限公司 | Linear cooling control method for environmental test chamber |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130118763A1 (en) * | 2011-11-11 | 2013-05-16 | Waterous Company | Proportional dynamic ratio control for compressed air foam delivery |
| CN111135503A (en) * | 2020-01-06 | 2020-05-12 | 天津理工大学 | Foam generator for preparing foam |
| 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 |
| CN215691263U (en) * | 2020-12-21 | 2022-02-01 | 润泰救援装备科技河北有限公司 | Integrated compressed air foam mixed fire extinguishing system |
| CN115006763A (en) * | 2022-06-17 | 2022-09-06 | 西安理工大学 | Compressed air foam fire extinguishing system capable of achieving automatic detection and control |
| WO2022218837A1 (en) * | 2021-04-13 | 2022-10-20 | Firedos Gmbh | Admixing system for fire-extinguishing units and method for the maintenance thereof |
-
2022
- 2022-10-28 CN CN202211340345.2A patent/CN115645802A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130118763A1 (en) * | 2011-11-11 | 2013-05-16 | Waterous Company | Proportional dynamic ratio control for compressed air foam delivery |
| CN111135503A (en) * | 2020-01-06 | 2020-05-12 | 天津理工大学 | Foam generator for preparing foam |
| CN215691263U (en) * | 2020-12-21 | 2022-02-01 | 润泰救援装备科技河北有限公司 | Integrated compressed air foam mixed fire extinguishing system |
| WO2022218837A1 (en) * | 2021-04-13 | 2022-10-20 | Firedos Gmbh | Admixing system for fire-extinguishing units and method for the maintenance thereof |
| 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 |
| CN115006763A (en) * | 2022-06-17 | 2022-09-06 | 西安理工大学 | Compressed air foam fire extinguishing system capable of achieving automatic detection and control |
Non-Patent Citations (1)
| Title |
|---|
| 李念慈: "《建筑消防给水系统的设计施工监理》", 中国建材工业出版社, pages: 439 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117873216A (en) * | 2024-02-01 | 2024-04-12 | 江苏拓米洛高端装备股份有限公司 | Linear cooling control method for environmental test chamber |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109012257B (en) | Automatic emulsion preparation precision control device and control method | |
| CN103529869A (en) | Pressure control means, flow control devices, pressure and flow control method | |
| CN105757851B (en) | A kind of chilled water variable-flow energy-saving control method and control system | |
| CN115645802A (en) | Integrated compressed air foam fire extinguishing system and control method thereof | |
| CN112556098B (en) | Dynamic hydraulic balance control method | |
| CN107158610A (en) | Compressed-air foam ratio hybrid control system | |
| CN103487269A (en) | Capacity-variable water cooling unit test system | |
| CN113359416A (en) | Multi-input single-output compressed air foam system based on PLC and control method | |
| CN111365931A (en) | Industrial cooling water balance optimization energy-saving control system | |
| CN211399756U (en) | Steam source switching control device of water supply system of 660MW supercritical unit | |
| CN108427443B (en) | High-precision automatic oxygenation device and automatic oxygenation method | |
| CN203586393U (en) | Heat balancing unit and control device thereof | |
| CN115597133B (en) | Variable frequency control system and control method for primary freezing pump of central air conditioner | |
| CN217715241U (en) | Cooling equipment | |
| CN207280009U (en) | A kind of new Regional Energy secondary pumping system | |
| CN113983675B (en) | Bypass differential pressure variable frequency air conditioner chilled water adjusting system and hydraulic balance method thereof | |
| CN215586009U (en) | Mixed acid system for semiconductor wet process | |
| CN221197025U (en) | Pressure air system in chemical fiber textile industry | |
| CN201170161Y (en) | Automatic control system for cooling water of gas compressor | |
| CN221628373U (en) | Large-caliber liquid flow standard device and diversion pressure stabilizing control device under small flow | |
| CN115569325B (en) | Wide-adaptability container type compressed air foam device and control method | |
| CN111707049B (en) | Refrigerant mass flow control system and method for pump barrel liquid supply refrigeration system | |
| CN220707318U (en) | Nuclear power station condensate pump system | |
| CN115704529B (en) | LNG constant temperature gasification's sea water heat transfer system | |
| CN217841754U (en) | Double-flow low-pressure cylinder water spraying temperature reduction system of steam turbine and steam turbine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |