CONTROL SYSTEM FOR USE DURING TUNNEL FIRE
20200391059 ยท 2020-12-17
Assignee
Inventors
Cpc classification
A62C37/36
HUMAN NECESSITIES
E21F11/00
FIXED CONSTRUCTIONS
A62C3/0207
HUMAN NECESSITIES
E21F1/00
FIXED CONSTRUCTIONS
International classification
A62C3/02
HUMAN NECESSITIES
A62C37/36
HUMAN NECESSITIES
E21F1/00
FIXED CONSTRUCTIONS
Abstract
A control system for use during a tunnel fire includes: measurement means 100.sub.1 to 100.sub.n installed in each of a plurality of management sections assigned in a tunnel, and for measuring one or both of a gas concentration and a smoke concentration in the management section using a light signal; and control means 102 for identifying a management section which includes a fire point, and controlling blowing means 101 capable of changing an air volume, based on one or both of the gas concentration and the smoke concentration measured by one or more measurement means installed in one or more management sections located downstream of the identified management section.
Claims
1. A control system for use during a tunnel fire, comprising: a measurement unit installed in each of a plurality of management sections assigned in a tunnel, and which measures one or both of a gas concentration and a smoke concentration in the management section using a light signal; and a controller which identifies a management section which includes a fire point, and controls a blower capable of changing an air volume, based on one or both of the gas concentration and the smoke concentration measured by one or more measurement means installed in one or more management sections located downstream of the identified management section.
2. The control system for use during a tunnel fire according to claim 1, further comprising an imaging unit installed in each of the plurality of management sections, and which acquires an image of the management section, wherein the controller identifies the management section which includes the fire point, based on the image.
3. The control system for use during a tunnel fire according to claim 1, wherein the measurement unit has a temperature measurement function of measuring a temperature in a space in which the light signal propagates, and wherein the controller identifies the management section which includes the fire point, based on the measured temperature.
4. The control system for use during a tunnel fire according to claim 3, wherein the measurement unit includes a light source for emitting light signals of different wavelengths, and wherein the controller identifies the management section which includes the fire point, based on the temperature obtained using at least one of the light signals.
5. The control system for use during a tunnel fire according to claim 4, wherein the controller controls the air volume of the blower, based on one or both of the gas concentration and the smoke concentration obtained using at least one of light signals of wavelengths different from a wavelength of the light signal used to identify the management section.
6. The control system for use during a tunnel fire according to claim 4, wherein the measurement unit emits the light signals of the different wavelengths, by changing an output wavelength of a wavelength variable light source in a time-division manner.
7. A control method for use during a tunnel fire, comprising: measuring, in each of a plurality of management sections assigned in a tunnel, one or both of a gas concentration and a smoke concentration in the management section using a light signal; identifying a management section which includes a fire point; and controlling a blower capable of changing an air volume, based on one or both of the gas concentration and the smoke concentration measured in one or more management sections located downstream of the identified management section.
8. The control method for use during a tunnel fire according to claim 7, wherein the management section which includes the fire point is identified based on an image acquired by an imaging unit installed in each of the plurality of management sections and for acquiring an image of the management section.
9. The control method for use during a tunnel fire according to claim 7, wherein a temperature in a space in which the light signal propagates is measured, and the management section which includes the fire point is identified based on the measured temperature.
10. The control method for use during a tunnel fire according to claim 9, wherein the management section which includes the fire point is identified based on the temperature obtained using at least one of light signals of different wavelengths.
11. The control method for use during a tunnel fire according to claim 10, wherein the air volume of the blower is controlled based on one or both of the gas concentration and the smoke concentration obtained using at least one of light signals of wavelengths different from a wavelength of the light signal used to identify the management section.
12. The control method for use during a tunnel fire according to claim 10, wherein the light signals of the different wavelengths are emitted by changing an output wavelength of a wavelength variable light source in a time-division manner.
13. The control system for use during a tunnel fire according to claim 5, wherein the measurement unit emits the light signals of the different wavelengths, by changing an output wavelength of a wavelength variable light source in a time-division manner.
14. The control method for use during a tunnel fire according to claim 11, wherein the light signals of the different wavelengths are emitted by changing an output wavelength of a wavelength variable light source in a time-division manner.
Description
BRIEF DESCRIPTION OF DRAWINGS
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DESCRIPTION OF EMBODIMENT
[0044] Exemplary embodiments of the present invention will be described below, with reference to the drawings.
Exemplary Embodiment 1
[0045]
[0046] In a tunnel 11 shown in
[0047]
[0048] Light signals propagate between the transmitter 12 and the receiver 13 in each of the long-range sensors 10 spaced at a predetermined distance inside the tunnel 11. In the receiver 13, the light detectors 223 and 224 that have received light signals via the condensers 221 and 222 photoelectrically convert the light signals, and output the resultant electrical signals to the signal processing units 225 and 226. The signal processing units 225 and 226 each calculate gas concentration and smoke concentration in the management section where the long-range sensor 10 is installed, using the corresponding electrical signal.
[0049] The signal processing units 225 and 226 and the controller 14 can be implemented by an electrical circuit (hardware), or implemented by a central processing unit (CPU) that performs processes according to a program.
[0050] The operation of the long-range sensor 10 will be described below.
[0051] The driver 213 controls the drive current and temperature of the laser light source 211. The laser light source 211 outputs a light signal of a predetermined wavelength (denoted as .sub.1 m). The light signal is converted into parallel light by the condenser 215, and then emitted into the atmosphere. When the light signal reaches the receiver 13, the light signal is condensed by the condenser 221. The light detector 223 photoelectrically converts the condensed light signal into an electrical signal. The signal processing unit 225 calculates the average value of carbon monoxide (CO) concentration between the transmitter 12 and the receiver 13, from the electrical signal.
[0052] The driver 214 controls the drive current and temperature of the laser light source 212. The laser light source 212 outputs a light signal of a predetermined wavelength (denoted as .sub.2 m). The light signal is converted into parallel light by the condenser 216, and then emitted into the atmosphere. When the light signal reaches the receiver 13, the light signal is condensed by the condenser 222. The light detector 224 photoelectrically converts the condensed light signal into an electrical signal. The signal processing unit 226 calculates the average value of carbon dioxide (CO.sub.2) concentration between the transmitter 12 and the receiver 13, from the electrical signal.
[0053] Moreover, the signal processing units 225 and 226 each calculate smoke concentration Cs from the transmittance of the light signal, according to Formula (1).
Is=Ioe.sup.CsD(1).
[0054] In Formula (1), Is is the intensity of the light signal emitted from the transmitter 12, Io is the intensity of the light signal received by the receiver 13, and D is the distance between the transmitter 12 and the receiver 13.
[0055] The operation of the controller 14 in Exemplary Embodiment 1 will be described below, with reference to a flowchart in
[0056] When a fire is detected through the monitoring camera 16 installed in the ith management section (management section i) in step S100 (see
[0057] Here, the fire breakout may be detected by the controller 14 receiving an image (still image or moving image) captured by the monitoring camera 16 and, for example, comparing the captured image with a predetermined reference image. Alternatively, the image captured by the monitoring camera 16 may be transmitted to a device in the in-tunnel system other than the controller 14 so that the device, upon detecting the fire breakout, outputs a signal indicating the fire breakout to the controller 14.
[0058] The controller 14 compares the maximum value of the collected CO gas concentrations (Cg) of the k sections with a preset gas concentration threshold Cg.sub.th (e.g. 10 ppm) (step S103). In the case where the maximum value is greater than the threshold, the controller 14 performs control to increase the output of the jet fan 15, in order to diffuse harmful gas (step S104). Specifically, the controller 14 provides a control signal including an instruction to increase the output (air volume), to the jet fan 15.
[0059] The controller 14 also compares the maximum value of the collected smoke concentrations (Cs) of the k sections with a preset smoke concentration threshold Cs.sub.th (e.g. 0.4 [l/m]) (step S105). In the case where the maximum value is greater than the threshold, the controller 14 performs control to increase the output of the jet fan 15, in order to diffuse smoke (step S104).
[0060] In the case where the gas concentration maximum value and the smoke concentration maximum value are each not greater than the threshold, the controller 14 performs control to decrease the output of the jet fan 15 (step S104). Specifically, the controller 14 provides a control signal including an instruction to decrease the output (air volume), to the jet fan 15. Since the output of the jet fan 15 is decreased, the diffusion range of harmful gas and smoke is reduced, and the supply of fresh air to the fire source is suppressed.
[0061] In the case where there is a predetermined safety standard, for example, the gas concentration maximum value and the smoke concentration maximum value are set so as to satisfy the safety standard.
[0062] Specific examples and effects of the control by the controller 14 will be described below, with reference to
[0063] In the case where the wind speed is 0 m/s, the generated gas and smoke spread concentrically from the fire point and reaches the side wall on which the long-range sensor 10 is installed, as shown in
[0064] This makes it difficult for the long-range sensor 10 installed on the side wall in the management section including the fire point to accurately measure the gas concentration and the smoke concentration.
[0065] As the wind speed increased, the point at which the gas reached the side wall shifted to the downstream side. Under a wind speed condition of 3 m/s, the gas reached the side wall, i.e. the long-range sensor 10, 25 m downstream.
[0066] The shift amount changes depending on the position of the fire point and the wind speed. Due to a change of the shift amount, the reliability of the measurement values of gas concentration and smoke concentration in the management section including the fire point (management section i in the example shown in
[0067] In the simulation conditions shown in
[0068] In this exemplary embodiment, the reliability of the sensor for monitoring the influence of the fire can be improved substantially, as a result of which safe evacuation of vehicle occupants near the fire breakout point can be achieved. This is because, while generating sufficient wind power to diffuse harmful gas and smoke which inhibit safe evacuation of occupants, harmful gas and smoke swept away downstream by wind are measured to ensure, for example, that the safety standard is satisfied.
[0069] Although the laser light sources 211 and 212 are used as the two light sources in Exemplary Embodiment 1, broadband light sources such as light emitting diodes (LEDs) or super luminescent diodes (SLDs) may be used. Moreover, the gas concentration may be measured by differential optical absorption spectroscopy (DOAS).
[0070] A light amplifier may be provided in the output stage of each of the laser light sources 211 and 212 and the input stage of each of the light detectors 223 and 224. The provision of the light amplifier improves the signal-to-noise ratio of the received light signal and improves the accuracy of the measurement result.
[0071] Although the structure in which the light signal propagates in one direction in the space between the transmitter 12 and the receiver 13 is used in Exemplary Embodiment 1, one or more mirrors may be provided between the transmitter 12 and the receiver 13. By causing the light signal to reflect off the one or more mirrors, the space propagation path of the light signal can be lengthened. As a result of lengthening the space propagation path of the light signal, target gas of lower concentration can be detected.
[0072] Although the two signal processing units 225 and 226 are provided to process light signals of two lines in Exemplary Embodiment 1, the signal processing units 225 and 226 may be integrated into one signal processing unit.
[0073] Although each of the light signals of two lines is used to measure the smoke concentration based on the transmittance of the light signal in Exemplary Embodiment 1, only the light signal of one line may be used. The controller 14 may use the average value of the smoke concentrations of the two lines, to improve the accuracy of the measurement value.
[0074] Although the gas used for controlling the jet fan 15 is CO and the gas concentration threshold is set to 10 [ppm] as an example in Exemplary Embodiment 1, the threshold may be another value. The controller 14 may use CO.sub.2 gas concentration in addition to CO gas concentration, for the control of the jet fan 15.
[0075] Although the smoke concentration threshold is set to 0.4 [l/m] in Exemplary Embodiment 1, the threshold may be another value. Although the controller 14 controls the jet fan 15 by monitoring both CO gas concentration and smoke concentration in Exemplary Embodiment 1, the controller 14 may control the jet fan 15 using any of CO gas concentration and the smoke concentration.
[0076] Although two different light sources are used to measure CO gas concentration and CO.sub.2 gas concentration in Exemplary Embodiment 1, one light source may be used. In such a case, for example, a wavelength variable light source is used, and the long-range sensor 10 controls the wavelength variable light source so that light signals of two wavelengths are emitted in a time-division manner as shown in
[0077] Although the light signal propagates between the transmitter 12 and the receiver 13 located away from each other in Exemplary Embodiment 1, one transceiver 71 and a reflector 72 may be used as shown in
Exemplary Embodiment 2
[0078]
[0079] In Exemplary Embodiment 1, the monitoring camera 16 is used to identify the management section which includes the fire point. In Exemplary Embodiment 2, the fire point is identified using information obtained by a long-range sensor 80, without using the monitoring camera 16.
[0080] As in Exemplary Embodiment 1, a jet fan 15 is installed in a tunnel 81 shown in
[0081]
[0082] In each of the long-range sensors 80 spaced at a predetermined distance inside the tunnel 11, the signal processing units 925 and 926 each calculate gas concentration, smoke concentration, and temperature (environmental temperature) in the management section where the long-range sensor 80 is installed, using the electrical signal from the corresponding one of the light detectors 223 and 224.
[0083] The operation of the long-range sensor 80 will be described below.
[0084] The signal processing units 925 and 926 measure the average space temperature between the transmitter 12 and the receiver 83, in addition to performing the gas concentration measurement and the smoke concentration measurement in Exemplary Embodiment 1.
[0085] The shape of an absorption spectrum of a gas molecule used when measuring gas concentration by WMS or DOAS varies depending on the environmental temperature, the atmospheric pressure, and the interaction with other gas molecules. Accordingly, the environmental temperature can be measured based on the received spectral intensity. In this exemplary embodiment, the signal processing units 925 and 926 measure the average value of temperature on the optical axis using two-line thermometry described in NPL 4, and set the average value of temperature as the environmental temperature. The method of measuring temperature using a technique employed when measuring gas concentration is not limited to two-line thermometry.
[0086] The operation of the controller 84 in Exemplary Embodiment 2 will be described below, with reference to a flowchart in
[0087] The controller 84 identifies a management section i which includes a fire point, using the environmental temperature measured by the long-range sensor 80 (step S101). The temperature of gas generated by a fire is highest at the fire point. The gas is cooled as its distance from the fire point increases. The controller 84 can therefore determine that the fire point is present in the management section in which the higher environmental temperature than the environmental temperature measured by the long-range sensor 80 in each of its surrounding management sections is measured.
[0088] The controller 84 then performs the process in steps S102 to S106, as in Exemplary Embodiment 1.
[0089] According to Exemplary Embodiment 2, an in-tunnel control system for detecting a fire and controlling an equipment can be constructed at low cost, in addition to the effects according to Exemplary Embodiment 1. This is because, in Exemplary Embodiment 2, the controller 84 identifies the fire point using the environmental temperature measured by the long-range sensor 80, and thus the monitoring camera is unnecessary.
[0090] Although the laser light sources 211 and 212 are used as the two light sources in Exemplary Embodiment 2, broadband light sources such as LEDs or SLDs may be used. Moreover, the gas concentration may be measured by DOAS.
[0091] A light amplifier may be provided in the output stage of each of the laser light sources 211 and 212 and the input stage of each of the light detectors 223 and 224 in Exemplary Embodiment 2, too. The provision of the light amplifier improves the signal-to-noise ratio of the received light signal and improves the accuracy of the measurement result.
[0092] Although the structure in which the light signal propagates in one direction in the space between the transmitter 12 and the receiver 83 is used in Exemplary Embodiment 2, one or more mirrors may be provided between the transmitter 12 and the receiver 83. By causing the light signal to reflect off the one or more mirrors, the space propagation path of the light signal can be lengthened. As a result of lengthening the space propagation path of the light signal, target gas of lower concentration can be detected.
[0093] Although the two signal processing units 925 and 926 are provided to process light signals of two lines in Exemplary Embodiment 2, the signal processing units 925 and 926 may be integrated into one signal processing unit.
[0094] Although each of the light signals of two lines that differ in wavelength is used to measure the smoke concentration and the environmental temperature in Exemplary Embodiment 2, only the light signal of one line may be used. The controller 84 may use the average value of the smoke concentrations of the two lines and the average value of the environmental temperatures of the two lines, to improve the accuracy of the measurement values.
[0095] In Exemplary Embodiment 2, the kind of gas used in the environmental temperature measurement and the kind of gas used in the control of the jet fan 15 may be different. For example, normal CO concentration in the atmosphere is very low, i.e. about 1 [ppm], which is likely to hinder accurate environmental temperature measurement. On the other hand, normal CO.sub.2 concentration in the atmosphere is high, i.e. about 400 [ppm], so that sufficient spectral intensity is observed. That is, more accurate environmental temperature measurement is possible in the case of using CO.sub.2 concentration than in the case of using CO concentration. Hence, CO.sub.2 gas and CO gas may be used respectively in the environmental temperature measurement and the control of the jet fan 15.
[0096] When using light signals of three or more lines that differ in wavelength, the controller 84 controls the air volume of the jet fan 15 based on one or both of the gas concentration and the smoke concentration obtained using at least one of the light signals of the plurality of lines different in wavelength from the light signal (the light signal used in the environmental temperature measurement) of the wavelength used to identify the management section which includes the fire point.
[0097] Although two different light sources are used to measure CO gas concentration and CO.sub.2 gas concentration in Exemplary Embodiment 2, one light source may be used. In such a case, for example, light signals of two wavelengths are emitted from the light source in a time-division manner, as shown in
[0098] Although the light signal propagates between the transmitter 12 and the receiver 83 located away from each other in Exemplary Embodiment 2, one transceiver 71 and a reflector 72 may be used as shown in
[0099]
[0100]
[0101] The foregoing exemplary embodiments can be wholly or partly described as, but not limited to, the following supplementary notes.
[0102] (Supplementary note 1) A control system for use during a tunnel fire, comprising: measurement means installed in each of a plurality of management sections assigned in a tunnel, and for measuring one or both of a gas concentration and a smoke concentration in the management section using a light signal; and
[0103] control means for identifying a management section which includes a fire point, and controlling blowing means capable of changing an air volume, based on one or both of the gas concentration and the smoke concentration measured by one or more measurement means installed in one or more management sections located downstream of the identified management section.
[0104] (Supplementary note 2) The control system for use during a tunnel fire according to supplementary note 1, further comprising imaging means installed in each of the plurality of management sections, and for acquiring an image of the management section,
[0105] wherein the control means identifies the management section which includes the fire point, based on the image.
[0106] (Supplementary note 3) The control system for use during a tunnel fire according to supplementary note 1, wherein the measurement means has a temperature measurement function of measuring a temperature in a space in which the light signal propagates, and
[0107] wherein the control means identifies the management section which includes the fire point, based on the measured temperature.
[0108] (Supplementary note 4) The control system for use during a tunnel fire according to supplementary note 3, wherein the measurement means includes a light source for emitting light signals of different wavelengths, and
[0109] wherein the control means identifies the management section which includes the fire point, based on the temperature obtained using at least one of the light signals.
[0110] (Supplementary note 5) The control system for use during a tunnel fire according to supplementary note 4, wherein the control means controls the air volume of the blowing means, based on one or both of the gas concentration and the smoke concentration obtained using at least one of light signals of wavelengths different from a wavelength of the light signal used to identify the management section.
[0111] (Supplementary note 6) The control system for use during a tunnel fire according to supplementary note 4 or 5, wherein the measurement means emits the light signals of the different wavelengths, by changing an output wavelength of a wavelength variable light source in a time-division manner.
[0112] (Supplementary note 7) A control method for use during a tunnel fire, comprising: measuring, in each of a plurality of management sections assigned in a tunnel, one or both of a gas concentration and a smoke concentration in the management section using a light signal;
[0113] identifying a management section which includes a fire point; and
[0114] controlling blowing means capable of changing an air volume, based on one or both of the gas concentration and the smoke concentration measured in one or more management sections located downstream of the identified management section.
[0115] (Supplementary note 8) The control method for use during a tunnel fire according to supplementary note 7, wherein
[0116] the management section which includes the fire point is identified based on an image acquired by imaging means installed in each of the plurality of management sections and for acquiring an image of the management section.
[0117] (Supplementary note 9) The control method for use during a tunnel fire according to supplementary note 7, a temperature in a space in which the light signal propagates is measured, and
[0118] the management section which includes the fire point is identified based on the measured temperature.
[0119] (Supplementary note 10) The control method for use during a tunnel fire according to supplementary note 9, wherein
[0120] the management section which includes the fire point is identified based on the temperature obtained using at least one of light signals of different wavelengths.
[0121] (Supplementary note 11) The control method for use during a tunnel fire according to supplementary note 10, wherein
[0122] the air volume of the blowing means is controlled based on one or both of the gas concentration and the smoke concentration obtained using at least one of light signals of wavelengths different from a wavelength of the light signal used to identify the management section.
[0123] (Supplementary note 12) The control method for use during a tunnel fire according to supplementary note 10 or 11, wherein
[0124] the light signals of the different wavelengths are emitted by changing an output wavelength of a wavelength variable light source in a time-division manner.
[0125] Although the present invention has been described with reference to the exemplary embodiments, the present invention is not limited to the exemplary embodiments. Various changes understandable by those skilled in the art can be made to the structures and details of the present invention within the scope of the present invention.
[0126] This application claims priority based on Japanese Patent Application No. 2017-237849 filed on Dec. 12, 2017, the disclosure of which is incorporated herein in its entirety.
REFERENCE SIGNS LIST
[0127] 10, 80 long-range sensor [0128] 11, 81 tunnel [0129] 12 transmitter [0130] 13, 83 receiver [0131] 14, 84 controller [0132] 15 jet fan [0133] 16 monitoring camera [0134] 71 transceiver [0135] 72 reflector [0136] 211, 212 laser light source [0137] 213, 214 driver [0138] 215, 216, 221, 222 condenser [0139] 223, 224 light detector [0140] 225, 226, 925, 926 signal processing unit