Smoke simulation device and experimental method for replacing real fire smoke

Abstract

A smoke simulation device and experimental method capable of replacing real fire smoke. The device comprises a glycol vapor type smoke simulation device shell, a glycol storage bottle, a switch, a glycol solution pump, a heater, a flow valve adjusting knob, a flow valve, a glycol vapor type smoke simulation device outlet pipeline, a booster fan, a fan drive signal receiving single-chip microcomputer, a smoke storage tank, a smoke concentration sensor and a controller. The device has the following effects: the rotational speed of the booster fan can be adjusted to simulate the thermal buoyancy effect of real fire smoke; the device is modularized, so it is easy to disassemble and maintain; and the experimental method is clear and easy to operate.

Description

Technical Field

[0001] This invention belongs to the field of civil aviation and civil fire safety testing technology, and specifically relates to a smoke simulation device and experimental method that can replace real fire smoke. Background Technology

[0002] In fields such as fire prevention in aircraft cargo holds and fire protection in civil buildings, smoke generation experiments are usually conducted to test the performance of smoke detectors in enclosed spaces. Since using real fire smoke would greatly increase the safety risks of the experiment, the use of smoke simulation devices that can replace real fire smoke is a common requirement in industrial practice.

[0003] The working principle of common smoke simulation devices on the market is as follows: inside the device, a mixture of ethylene glycol and water (smoke oil) is heated to form steam, which is then ejected. The ethylene glycol steam cools and re-sublimates to form smoke. However, compared with real fire smoke, this type of smoke simulation device lacks the upward thermal buoyancy effect of the fire source, resulting in significant differences between simulated smoke and real fire smoke in terms of motion patterns and concentration fields.

[0004] Therefore, in industrial practice, when using smoke simulation devices to replace real fire smoke, modifications are usually made to the smoke simulation devices based on the ethylene glycol spray principle. These modifications can be broadly categorized into three approaches: 1) Injecting helium before the ethylene glycol vapor is emitted to reduce the density of the simulated smoke vapor and increase its buoyancy, thus simulating the high-temperature thermal buoyancy effect of real fire smoke; 2) Adding a heating device to the outlet of the ethylene glycol vapor-type smoke simulation device to heat the vapor, thereby simulating the high-temperature thermal buoyancy effect of real fire smoke; 3) Directly adjusting the outlet flow rate of the ethylene glycol vapor-type smoke simulation device to compensate for the missing thermal buoyancy effect with a larger flow rate.

[0005] However, the above three modification approaches have certain drawbacks in practical use. First, the helium filling method significantly increases the complexity of the device, and the storage and release of helium increase maintenance costs. Second, temperature change is a slow physical process, exhibiting a significant hysteresis characteristic in the simulated smoke heating method, making the device difficult to adjust. Finally, none of the above three types of smoke simulation devices are conducive to closed-loop control of smoke concentration. However, the development of a real fire is a non-steady-state process, typically going through different stages. The smoke concentration released during the smoldering, development, and complete combustion stages differs. From a control perspective, this means the control target is dynamically changing, and only through closed-loop control can the smoke concentration approximation of a real fire be achieved. Therefore, developing entirely new smoke simulation devices and establishing standardized experimental methods are urgent needs in this industry. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a smoke simulation device and experimental method that can replace real fire smoke.

[0007] To achieve the above objectives, the present invention provides a smoke simulation device that can replace real fire smoke, comprising an ethylene glycol vapor-type smoke simulation device housing, an ethylene glycol storage bottle, a switch, an ethylene glycol solution pump, a heater, a flow valve adjustment knob, a flow valve, an ethylene glycol vapor-type smoke simulation device outlet pipe, a booster fan, a fan drive signal receiving microcontroller, a smoke storage box, a smoke concentration sensor, and a controller; wherein, the ethylene glycol storage bottle is disposed inside the ethylene glycol vapor-type smoke simulation device housing, and contains ethylene glycol solution; one end of the ethylene glycol vapor-type smoke simulation device outlet pipe is connected to the upper end of the ethylene glycol storage bottle. The other end is inserted into the inside of the smoke storage box; the ethylene glycol solution pump, heater, and flow valve are sequentially installed on the outlet pipe of the ethylene glycol vapor-type smoke simulator, and the flow valve is equipped with a flow valve adjustment knob; the switch is installed on the outer shell of the ethylene glycol vapor-type smoke simulator and is connected to the ethylene glycol solution pump and heater to control the start and stop of the ethylene glycol solution pump and heater; the upper end of the smoke storage box has an opening, and the booster fan is installed at the opening; the fan drive signal receiving microcontroller is installed on the smoke storage box and is electrically connected to the booster fan; the controller is electrically connected to the fan drive signal receiving microcontroller and the smoke concentration sensor respectively.

[0008] The controller is a computer.

[0009] The experimental method using the above-mentioned smoke simulation device, which can replace real fire smoke, includes the following steps performed in sequence:

[0010] 1) S01: To determine the control target of the smoke simulation device, a real fire smoke experiment should be conducted first. Place the smoke concentration sensor in the test environment and conduct a real fire smoke experiment. Record the smoke concentration reading of the smoke concentration sensor during the entire fire process, and use this reading as the control target of the smoke simulation device;

[0011] 2) S02: Define a booster fan control command on the controller that covers multiple frequency ranges or sweep frequency signals. Place the smoke concentration sensor inside the smoke storage box, and then turn on the switch to start the ethylene glycol solution pump and heater. The ethylene glycol solution pump draws the ethylene glycol solution from the ethylene glycol storage bottle into the outlet pipe of the ethylene glycol vapor-type smoke simulator, and then delivers it to the heater. The ethylene glycol solution is heated to complete evaporation in the heater, and then sprayed into the smoke storage box through the flow valve. It cools in the air and re-condenses into droplets, thus forming smoke. Record the smoke concentration reading of the smoke concentration sensor throughout the process.

[0012] 3) S03: Using the custom booster fan control command in S02 as input and the smoke concentration reading from the smoke concentration sensor as output, the transfer function model between input and output is identified using the system identification method.

[0013] 4) S04: Using the pole placement method in the automatic control principle, pole placement is performed on the transfer function obtained in S03. The result of pole placement is the control law for closed-loop control of smoke concentration.

[0014] 5) S05: Write the control law obtained in S04 into the controller. The controller will generate control instructions according to the control law and send them to the fan drive signal receiving microcontroller, which will eventually drive the operation of the booster fan. Record the smoke concentration reading of the smoke concentration sensor during this process.

[0015] 6) S06: Determine whether the smoke concentration reading of the smoke concentration sensor in S05 is consistent with the smoke concentration reading in the real fire smoke experiment in S01. If they are consistent, it means that the whole device has achieved smoke concentration closed-loop control equivalent to real fire smoke. If they are inconsistent, return to S04 to redesign the control law until the smoke concentration reading of the smoke concentration sensor is consistent with the smoke concentration in the real fire smoke experiment in S01.

[0016] The smoke simulation device and experimental method provided by this invention, which can replace real fire smoke, have the following beneficial effects:

[0017] 1) By adjusting the speed of the booster fan, the thermal buoyancy effect of real fire smoke can be approximated;

[0018] 2) The entire device adopts a modular design, making it easy to disassemble and maintain;

[0019] 3) Due to the fast adjustment of the booster fan speed, the whole device can easily achieve closed-loop control of smoke concentration in a specific space. The smoke concentration sensor senses the smoke concentration in the measured space and feeds it back to the controller. The controller sends control commands to the booster fan according to the control law. By adjusting the fan speed, the dynamic simulation of smoke concentration in the smoldering stage, development stage and complete combustion stage of a real fire can be achieved.

[0020] 4) The experimental methods are clear and easy to operate. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the smoke simulation device provided by the present invention, which can replace real fire smoke.

[0022] Figure 2 A flowchart illustrating the experimental method for using the smoke simulation device provided by this invention, which can replace real fire smoke. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 1 As shown, the smoke simulation device provided by this invention, which can replace real fire smoke, includes an ethylene glycol vapor-type smoke simulation device housing 1, an ethylene glycol storage bottle 2, a switch 3, an ethylene glycol solution pump 4, a heater 5, a flow valve adjustment knob 6, a flow valve 7, an ethylene glycol vapor-type smoke simulation device outlet pipe 8, a booster fan 9, a fan drive signal receiving microcontroller 10, a smoke storage box 11, a smoke concentration sensor 12, and a controller 13; wherein, the ethylene glycol storage bottle 2 is disposed inside the ethylene glycol vapor-type smoke simulation device housing 1, and contains ethylene glycol solution; one end of the ethylene glycol vapor-type smoke simulation device outlet pipe 8 is connected to the upper end of the ethylene glycol storage bottle 2, and the other end is inserted into the... Inside the smoke storage box 11: ethylene glycol solution pump 4, heater 5, and flow valve 7 are sequentially installed on the outlet pipe 8 of the ethylene glycol vapor-type smoke simulator. The flow valve 7 is equipped with a flow valve adjustment knob 6. Switch 3 is installed on the outer casing 1 of the ethylene glycol vapor-type smoke simulator and is connected to the ethylene glycol solution pump 4 and heater 5 to control the start and stop of the ethylene glycol solution pump 4 and heater 5. The upper end of the smoke storage box 11 has an opening, and a booster fan 9 is installed at the opening. A fan drive signal receiving microcontroller 10 is installed on the smoke storage box 11 and is electrically connected to the booster fan 9. Controller 13 is electrically connected to the fan drive signal receiving microcontroller 10 and the smoke concentration sensor 12, respectively.

[0025] The controller 13 is a computer.

[0026] The working principle of the smoke simulation device provided by this invention, which can replace real fire smoke, is described below.

[0027] When a smoke simulation experiment is required, the smoke concentration sensor 12 is placed inside the smoke storage box 11; the switch 3 is turned on to start the ethylene glycol solution pump 4 and the heater 5. The ethylene glycol solution pump 4 draws the ethylene glycol solution in the ethylene glycol storage bottle 2 into the outlet pipe 8 of the ethylene glycol vapor-type smoke simulation device, and then delivers it to the heater 5. The ethylene glycol solution is heated in the heater 5 until it is completely evaporated, and then sprayed into the smoke storage box 11 through the flow valve 7. It cools in the air and re-condenses into droplets, thus forming smoke. The experimenter can adjust the opening of the flow valve 7 by adjusting the flow valve adjustment knob 6, thereby adjusting the outlet flow rate of the smoke. In the above process, under the control of controller 13, the smoke concentration sensor 12 detects the smoke concentration value in the smoke storage box 11 and then transmits it to controller 13. Controller 13 generates a control signal based on the smoke concentration value and sends it to the fan drive signal receiving microcontroller 10. The fan drive signal receiving microcontroller 10 sends a control command to the booster fan 9 to adjust the speed of the booster fan 9, thereby simulating the thermal buoyancy effect of smoke in a real fire. If the smoke buoyancy effect is insufficient, controller 13 will automatically adjust the speed of booster fan 9 to increase it; if the smoke buoyancy effect is too large, controller 13 will automatically adjust the speed of booster fan 9 to decrease it.

[0028] like Figure 2 As shown, the experimental method using the aforementioned smoke simulation device, which can replace real fire smoke, includes the following steps performed in sequence:

[0029] 1) S01: To determine the control target of the smoke simulation device, a real fire smoke experiment should be conducted first. The smoke concentration sensor 12 is placed in the test environment, and a real fire smoke experiment is conducted. During the experiment, the smoke concentration reading of the smoke concentration sensor 12 during the complete fire process is recorded, and this reading is used as the control target of the smoke simulation device. The ultimate goal of the smoke simulation device is to achieve a match between the simulated smoke concentration in the test environment and the real fire smoke concentration by adjusting the speed of the booster fan 9.

[0030] 2) S02: Define a control command for the booster fan 9 that covers multiple frequency ranges or sweep frequency signals on the controller 13. Place the smoke concentration sensor 12 inside the smoke storage box 11. Then turn on the switch 3 to start the ethylene glycol solution pump 4 and the heater 5. The ethylene glycol solution pump 4 draws the ethylene glycol solution in the ethylene glycol storage bottle 2 into the outlet pipe 8 of the ethylene glycol vapor type smoke simulation device, and then delivers it to the heater 5. The ethylene glycol solution is heated to complete evaporation in the heater 5, and then sprayed into the smoke storage box 11 through the flow valve 7. It cools in the air and re-condenses into droplets, thus forming smoke. Record the smoke concentration reading of the smoke concentration sensor 12 throughout the process.

[0031] 3) S03: Using the custom-defined booster fan 9 control command in S02 as input and the smoke concentration reading of the smoke concentration sensor 12 as output, the transfer function model between input and output is identified by the system identification method.

[0032] 4) S04: Using the pole placement method in the automatic control principle, pole placement is performed on the transfer function obtained in S03. The result of pole placement is the control law for closed-loop control of smoke concentration.

[0033] 5) S05: Write the control law obtained in S04 into the controller 13. The controller 13 will generate control instructions according to the control law and send them to the fan drive signal receiving microcontroller 10, which will eventually drive the operation of the booster fan 9 and record the smoke concentration reading of the smoke concentration sensor 12 during the process.

[0034] 6) S06: Determine whether the smoke concentration reading of the smoke concentration sensor 12 in S05 is consistent with the smoke concentration reading in the real fire smoke experiment in S01. If they are consistent, it means that the whole device has achieved smoke concentration closed-loop control equivalent to real fire smoke. If they are inconsistent, return to S04 to redesign the control law until the smoke concentration reading of the smoke concentration sensor 12 is consistent with the smoke concentration in the real fire smoke experiment in S01.

Claims

1. An experimental method using a smoke simulation device that can replace real fire smoke, wherein the smoke simulation device includes an ethylene glycol vapor type smoke simulation device shell (1), an ethylene glycol storage bottle (2), a switch (3), an ethylene glycol solution pump (4), a heater (5), a flow valve adjustment knob (6), a flow valve (7), an ethylene glycol vapor type smoke simulation device outlet pipe (8), a booster fan (9), a fan drive signal receiving microcontroller (10), a smoke storage box (11), a smoke concentration sensor (12), and a controller (13); wherein, An ethylene glycol storage bottle (2) is placed inside the outer shell (1) of the ethylene glycol vapor-type smoke simulator, containing an ethylene glycol solution. One end of the outlet pipe (8) of the ethylene glycol vapor-type smoke simulator is connected to the upper end of the ethylene glycol storage bottle (2), and the other end is inserted into the smoke storage box (11). An ethylene glycol solution pump (4), a heater (5), and a flow valve (7) are installed sequentially on the outlet pipe (8) of the ethylene glycol vapor-type smoke simulator. A flow valve adjustment knob (6) is provided on the flow valve (7). A switch (3) is installed on the ethylene glycol vapor-type smoke simulator. The outer casing (1) is connected to the ethylene glycol solution pump (4) and the heater (5) to control the start and stop of the ethylene glycol solution pump (4) and the heater (5); the upper end of the smoke storage box (11) is provided with an opening, and the booster fan (9) is installed at the opening; the fan drive signal receiving microcontroller (10) is installed on the smoke storage box (11) and is electrically connected to the booster fan (9); the controller (13) is electrically connected to the fan drive signal receiving microcontroller (10) and the smoke concentration sensor (12) respectively; the characteristic is that the experimental method includes the following steps performed in sequence: 1) S01: Place the smoke concentration sensor (12) in the test environment and conduct a real fire smoke experiment. Record the smoke concentration reading of the smoke concentration sensor (12) during the complete fire process and use the reading as the control target of the smoke simulation device. 2) S02: Define a booster fan (9) control command on the controller (13) that covers multiple frequency ranges or sweep frequency signals, place the smoke concentration sensor (12) inside the smoke storage box (11), and then turn on the switch (3) to start the ethylene glycol solution pump (4) and heater (5). The ethylene glycol solution pump (4) draws the ethylene glycol solution in the ethylene glycol storage bottle (2) into the outlet pipe (8) of the ethylene glycol vapor type smoke simulation device, and then delivers it to the heater (5). The ethylene glycol solution is heated to complete evaporation in the heater (5), and then sprayed into the smoke storage box (11) through the flow valve (7). It cools in the air and re-condenses into droplets, thus forming smoke. Record the smoke concentration reading of the smoke concentration sensor (12) throughout the process. 3) S03: The custom booster fan (9) control command in S02 is used as input, and the smoke concentration reading of the smoke concentration sensor (12) is used as output. The system identification method is used to identify the transfer function model between input and output. 4) S04: Using the pole placement method in the automatic control principle, pole placement is performed on the transfer function obtained in S03. The result of pole placement is the control law for closed-loop control of smoke concentration. 5) S05: Write the control law obtained in S04 into the controller (13). The controller (13) will generate control instructions according to the control law and send them to the fan drive signal receiving microcontroller (10), which will eventually drive the operation of the booster fan (9) and record the smoke concentration reading of the smoke concentration sensor (12) during the process. 6) S06: Determine whether the smoke concentration reading of the smoke concentration sensor (12) in S05 is consistent with the smoke concentration reading in the real fire smoke experiment in S01. If they are consistent, it means that the whole device has achieved smoke concentration closed-loop control equivalent to real fire smoke. If they are inconsistent, return to S04 to redesign the control law until the smoke concentration reading of the smoke concentration sensor (12) is consistent with the smoke concentration in the real fire smoke experiment in S01.

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