JP2018096857A - Fog transmittance measuring device and road tunnel ventilation system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fog transmittance measuring device used for measuring luminous transmittance in a road tunnel, which has a light projection part and a light receiving part which are generally installed 100 m separated away from each other; the fog transmittance measuring device capable of being installed at point of a tunnel with a small curve radius which a straight line of 100 m is hardly ensured.SOLUTION: A signal processing part 13 carries out a series of calculation processing on a dust density in an ambient space obtained by a sensor part 12 in a manner of moving average and calculation. With this, 100 m luminous transmittance, i.e., fog transmittance can be obtained same as a conventional general fog transmittance measuring device.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a haze transmittance measuring device used for measuring luminous transmittance in a road tunnel and a road tunnel ventilation system using the same.

  2. Description of the Related Art Conventionally, a haze transmittance measuring apparatus used for measuring luminous transmittance in a road tunnel is generally installed with a light projecting unit and a light receiving unit separated by 100 m (see, for example, Patent Document 1 and Patent Document 2). That is, the haze transmittance in the road tunnel uses a luminous transmittance 100 m ahead (in other words, the degree of arrival of light at a position 100 m away from the light source). FIG. 4 is a block diagram of a conventional haze transmittance measuring apparatus. The transmittance is changed by the light projected from the light source 102 of the light projecting unit 101 due to the absorption or scattering of soot particulates present in the road tunnel, and an electric signal corresponding to the change in the light receiving element 104 of the light receiving unit 103. And is obtained by performing arithmetic processing in the processing unit 105. The road tunnel ventilation control device operates a ventilator to improve the visual environment in the road tunnel based on this transmittance.

JP 59-116037 A JP-A-61-137049

  Such a conventional haze transmittance measuring device has a configuration of a light projecting unit and a light receiving unit. Therefore, in order to measure the luminous transmittance (fumes transmittance) 100 m ahead with the conventional haze transmittance measuring device, a straight line of 100 m without an obstacle is required between the light projecting portion and the light receiving portion. . When the tunnel is curved, it is difficult to secure a straight portion of 100 m, and there is a problem that the light projecting unit and the light receiving unit cannot be installed. In recent years, road tunnels are often built underground in urban areas, and in such tunnels, it is particularly difficult to secure a straight portion of 100 m.

  Therefore, the present invention solves the above-described conventional problems, and by measuring the dust concentration around one place in the tunnel without using a pair of light emitting unit and light receiving unit, a visual sense of 100 m ahead An object is to provide a method for measuring transmittance.

  In order to achieve this object, the present invention provides a smoke transmittance having a sensor unit for measuring the dust concentration in the surrounding space and a signal processing unit for converting the dust concentration measured by the sensor unit into a smoke transmittance. In the measuring device, the signal processing unit converts the instantaneous value of the dust concentration measured by the sensor unit to a moving average by moving average, thereby achieving the intended purpose. is there.

  According to the present invention, there is provided a smoke transmittance measuring device having a sensor unit for measuring the dust concentration in the surrounding space, and a signal processing unit for converting the dust concentration measured by the sensor unit into a smoke transmittance. The processing unit measures the ambient dust concentration at one location by moving and averaging the instantaneous value of the dust concentration measured by the sensor unit into a haze transmittance. Smoke transmittance can be obtained.

Configuration diagram of the haze transmittance measuring apparatus according to Embodiment 1 of the present invention The graph which shows the conversion process from the dust concentration by Embodiment 1 of this invention to 100m transmittance | permeability (a) The graph of the dust concentration instantaneous value based on a sensor value (b) The graph of the moving average value of a dust concentration (c) Dust concentration Graph of transmittance calculated from moving average value of Configuration diagram of road tunnel ventilation system according to Embodiment 1 of the present invention Configuration of conventional haze transmittance measuring device

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a configuration diagram of a haze transmittance measuring apparatus for a road tunnel.

  The haze transmittance measuring device 11 includes a sensor unit 12 and a signal processing unit 13. The sensor unit 12 is a dust concentration sensor using a light scattering method, and measures the dust concentration around the haze transmittance measuring device 11. The dust concentration is expressed by the weight of dust per unit volume or the number of dust. On the other hand, the haze transmittance is a degree of visibility at a position 100 m away, and the degree of visibility becomes lower as the surrounding dust concentration is higher.

To determine the transmittance from the dust concentration, it is determined based on the Lambert-Beer law. That is, according to this Lambert-Beer law, in the light absorption, the logarithm of the ratio of the intensity of light incident on a substance and the intensity of transmitted light is proportional to the product of the thickness and concentration of the substance. The transmittance is a ratio between the intensity of light incident on this substance and the intensity of transmitted light. Here, it is considered that the following equation holds when the haze transmittance of 100 m ahead is considered.

  The concentration coefficient “a” is a constant when the transmittance is obtained using the dust concentration.

  In the haze transmittance measuring device 11, the haze transmittance is obtained as follows. First, the signal processing unit 13 collects electrical signals corresponding to the dust concentration output from the sensor unit 12. The obtained dust concentration is a local instantaneous value at the installation location of the haze transmittance measuring device 11. On the other hand, as described above, the haze transmittance is the transmittance of a straight section of 100 m. Therefore, it is considered that the haze transmittance can be obtained by using the average value of the dust concentration in the straight section of 100 m. If this is explained by focusing on the movement of air in the tunnel, the dust and smoke that affect the haze transmittance in the tunnel move by a flow of air in the tunnel at a distance of 100 m to be measured. Therefore, by setting the instantaneous value of the dust concentration as the moving average when moving 100 m, the dust concentration corresponding to the desired haze transmittance can be obtained.

Further, the signal processing unit 13 performs a calculation process on the dust concentration obtained by the moving average according to the calculation formula (1) to obtain the smoke transmittance.

  In this way, the dust concentration c obtained by the sensor unit 12 is moved and averaged by the signal processing unit 13, whereby a transmittance equivalent to that of the conventional haze transmittance measuring device can be obtained.

  FIG. 2 is a graph comparing the transmittance obtained by simultaneously measuring the smoke transmittance measuring device of the present embodiment and the conventional smoke transmittance measuring device configured of the light projecting unit and the light receiving unit at the same place. It is. 2 (a) is the instantaneous value of the dust concentration, FIG. 2 (b) is the moving average value of the dust concentration, and FIG. 2 (c) is obtained from the moving average value of the dust concentration by the calculation formula (1). It is a graph of haze transmittance. As shown in FIG. 2, the tendency of the transmittance (solid line) obtained with the haze transmittance measuring device according to the present invention and the transmittance (broken line) obtained with the conventional haze transmittance measuring device coincide with each other. It turns out that the haze transmittance measuring device of the present invention is effective. The averaging time to be averaged by the signal processing unit 13 can be arbitrarily set in the range of 5 seconds to 1000 seconds according to the actual wind speed in the tunnel.

  According to the haze transmittance measuring apparatus of the present embodiment, the haze transmittance can be measured by measuring the ambient dust concentration at one place in the tunnel even in a place that is curved in the tunnel.

  FIG. 3 is a configuration diagram of a road tunnel ventilation system in which the haze transmittance measuring device 11 according to the present embodiment is applied to a road tunnel. 3, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  According to FIG. 3, the haze transmittance measuring device 11 and the wind direction and wind speed measuring device 15 are attached to the wall surface in the road tunnel 17. The dust concentration measured by the sensor unit 12 is processed by the signal processing unit 13 to obtain the transmittance. At this time, when obtaining the moving average, the time for the air in the tunnel to pass through a distance of 100 m is calculated according to the wind speed in the tunnel, and the average value within the calculated time is obtained. The transmittance calculated by the signal processing unit 13 is transmitted to the ventilation control device 14, and the ventilation control device 14 determines the operating air volume of the ventilator 16 necessary for improving the visual environment in the road tunnel 17. The control of the operating air volume may be performed by changing the number of operating units using a plurality of ventilators 16. Alternatively, an air volume changing device (specifically, for example, inverter control) may be provided in each ventilator 16, and the operation air volume of each ventilator 16 may be changed.

  In FIG. 3, the signal processing unit 13 is configured to be housed in the haze transmittance measuring device 11, but may be a component of the ventilation control device 14.

  Moreover, in this Embodiment, although the wind speed in a tunnel was calculated | required by the wind direction wind speed measuring apparatus 15, you may obtain | require the wind speed in a tunnel from the driving | running air volume of the ventilator 16. FIG.

  According to the road tunnel ventilation system of the present embodiment, even in a curved place in the tunnel, the luminous transmittance of 100 meters ahead can be obtained with higher accuracy by measuring the dust concentration around one place in the tunnel. It is possible to measure, and automatic operation control of the ventilator can be performed more accurately.

  According to the present invention, it is possible to measure the luminous transmittance 100 m ahead even in a curved tunnel by measuring the concentration of dust around one place in the tunnel, and automatically with higher accuracy than a ventilator. Operation control is possible.

DESCRIPTION OF SYMBOLS 11 Smoke | transmittance measuring device 12 Sensor part 13 Signal processing part 14 Ventilation control apparatus 15 Wind direction wind speed measuring apparatus 16 Ventilator 17 Road tunnel 101 Light projection part 102 Light source 103 Light receiving part 104 Light receiving element 105 Processing part

Claims (4)

A sensor unit for measuring the dust concentration in the surrounding space;
A haze transmittance measuring device having a signal processing unit that converts the dust concentration measured by the sensor unit into a haze transmittance,
The signal processing unit is a transmittance measuring apparatus that converts an instantaneous value of the dust concentration measured by the sensor unit into a haze transmittance by moving average. 2. A ventilation device for ventilating air in a tunnel in a road tunnel, a wind direction and wind speed measuring device for measuring the wind direction and wind velocity in the tunnel, and a haze permeability measuring device according to claim 1 for measuring the haze permeability in the tunnel. And a road tunnel ventilation system having a ventilation control device for controlling the operation of the ventilator,
From the wind speed value obtained by the wind direction wind speed measuring device, the time for the tunnel air to pass through a predetermined distance is calculated, and the instantaneous value of the dust concentration in the tunnel obtained by the fume permeability measuring device is calculated and moved. Road tunnel ventilation system that averages and calculates haze transmission. In a road tunnel, a ventilator for ventilating the air in the tunnel, a haze permeability measuring device according to claim 1 for measuring a haze permeation rate at a constant distance in the tunnel, and a ventilation control device for controlling the operation of the ventilator In a road tunnel ventilation system having
Calculate the operating air volume of the ventilator, determine the wind speed in the road tunnel from the operating air volume,
From the obtained wind speed value, calculate the time for the air in the tunnel to pass through a predetermined distance, and calculate the instantaneous value of the dust concentration in the tunnel obtained by the haze permeability measuring device to calculate the moving average for the haze permeability. Calculate the road tunnel ventilation system. The ventilation control device is a road tunnel ventilation system that controls operation of the ventilator based on the calculated haze transmittance.

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