JP2788004B2 - Ventilation air volume control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of civil engineering works, such as mountain tunnels, underground power plants, oil storage tunnels, and ventilation air flow control in constructions other than these that require ventilation or air supply and exhaust during construction of tunnels. About the method.

[0002]

2. Description of the Related Art In FIG. 6, an air blower tube 2 of an air blower 1 is opened at a face K of a tunnel T, and an exhaust blower 3 is installed near the face K. An exhaust air tube 4 of the exhaust blower 3 extends outside the tunnel T. Then, in the vicinity of the face K, that is, the distance R1
A dust sensor S is provided at a position (for example, 50 m).

During excavation, the operation of the exhaust blower 3 is controlled based on the amount of dust detected by the dust sensor S.

[0004]

However, the conventional method has the following problems. (1) Since the area where a large number of workers actually work is within a distance R (approximately 200 m) from the face K, when the exhaust blower 3 is driven by the detection value of the dust concentration sensor S, the dust concentration rises and falls. And the power consumption increases. (2) Since the length of the exhaust pipe 4 is increased by the tunnel excavation length and the pressure loss changes, the power consumption increases unless the required maximum number of revolutions is changed frequently to match the length of the wind pipe. (3) Since the dust is distributed to a certain extent as a lump, the exhaust fan 3 is linearly arranged with the value indicated by the dust sensor S.
When the operation control is performed, the change in rotation becomes fine, not only the load on the motor becomes large, but also the power consumption becomes large.

An object of the present invention is to provide a ventilation air volume control method capable of reducing power consumption.

[0006]

According to a first method of the present invention, a dust concentration sensor is arranged behind an area to be surely evacuated away from a face, and a diameter of an air supply and exhaust air tube is provided. Measuring the length and material corresponding to the tunnel excavation length, calculating the pressure loss of the wind pipe, and detecting the dust concentration per unit time required for the dust concentration detected by the dust concentration sensor to sufficiently clear the set reference value. The amount of exhaust air and the operation time are calculated, and the number of revolutions of the air blower and the exhaust blower is limited to control so that the dust concentration does not rise above a set reference value.

According to the second method of the present invention, a dust concentration sensor is disposed behind an area to be surely evacuated away from the face, and based on a signal from the dust concentration sensor, the dust concentration becomes a set abnormal value. If it reaches, the operation is performed with the rotation speed of the exhaust blower at the maximum, and even if the dust concentration falls below the set abnormal value, the overrunning operation is continued for a certain time to reliably exhaust the dust, and after the overrunning operation is completed. Is characterized in that normal operation control is performed according to the set reference value of the dust concentration.

[0008]

In the present invention, the dust concentration sensor is provided at the rear of a place where there are many workers separated from the face to be surely evacuated, and it is possible to reliably detect a high density having a partial unevenness in the dust filling area.

Further, the operation control is performed with the maximum capacity of the exhaust blower suppressed by the tunnel excavation length and the diameter of the exhaust air pipe, thereby reducing the electric energy.

Further, by performing the overtaking operation and adding a control having a certain width, a control requiring a fine change is eliminated, and the amount of power can be reduced.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In these drawings, parts corresponding to those in FIG. 6 are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 shows an apparatus for implementing the first method of the present invention. A dust concentration sensor 10 is provided at a distance R from a face K. The distance R is set rearward (for example, 200 m) with respect to the conventional distance R1 (for example, 50 m) so that a large number of workers can reliably detect the dust concentration in an area to be evacuated. . The sensor 10 is connected to a control device 11, and the air blower 1 and the exhaust blower 3 are connected to the control device 11 via inverters 12 and 13, respectively. In addition, the code | symbol L in a figure is the length of the exhaust air pipe 4, and d is the diameter of the exhaust air pipe 4. FIG.

Next, the mode of control will be described with reference to FIG.

First, the diameter d of the exhaust air tube 4, the length L of the air tube corresponding to the tunnel excavation length, and the material are measured (step S1). Next, when the measurement result is input to the control device 11, the control device 11 calculates the minimum rotation speed Fmin of the wind tube expansion and the maximum rotation speed Fmax (FIG. 4) corresponding to the tunnel excavation length from the pressure loss caused by the exhaust air tube 4. Calculation is performed (step S2). Next, the fan air volume and the operation time of the exhaust blower 3 necessary for the dust concentration detected by the dust concentration sensor 10 to sufficiently satisfy the rule are calculated (step S).
3). That is, the rule is that CO (carbon monoxide) is 1
00ppm or less (Occupational Safety and Health Regulations), but 50ppm
Or less (Japan Society for Occupational Health), and NOx (nitrogen oxide) is 25 ppm or less.
Tunnel Technology Association), and the evacuation time is 10 to 20 minutes, preferably about 10 minutes. Therefore, the maximum number of rotations of the exhaust blower 3 is controlled, and monitoring is performed so that the dust concentration does not decrease to an unnecessary degree at the number of rotations with an excessive capacity. Therefore,
The power consumption is reduced.

FIG. 3 shows an apparatus for implementing the second method of the present invention. This device is configured substantially the same as that of FIG. 1, and only the control mode of the control device 11A is different.

Next, the mode of control will be described with reference to FIGS. Note that the characteristic A in FIG. 5 is the rotation speed of the exhaust blower, and the characteristic B is the dust concentration. Manually, both blowers 1,
3 is started, and after the time T1, the expansion of the exhaust air tube 4 ends,
When the blasting is performed, the rotation of the exhaust blower 3 is increased to the maximum rotation number, and the exhaust blower 3 is operated for a certain time (T2). Therefore, the control device 11A detects the dust concentration D based on the signal from the dust concentration sensor 10 (Step S10). Next, in the illustrated example, when the concentration decreases and the concentration D reaches the set dust amount Dmax, a set time T3 (this time T3 is the predetermined time T3).
(No relationship with the dust concentration) starts the exhaust cutoff operation, and drives out the dust in the air duct 4 to the outside of the tunnel T (step S11). Next, the overtaking operation is completed, and it is determined whether or not the dust concentration has definitely decreased from the set dust amount Dmax (step S12). If NO, the process returns to step S11, and if YES, the linear operation B1 corresponding to the dust concentration D is performed (step S13).

[0017]

As described above, according to the present invention, the dust concentration to be exhausted is reliably detected, the operation control is performed with the maximum capacity of the blower being suppressed in accordance with the excavation length, and after the exhaust cutoff operation, By performing the linear operation according to the dust concentration, the power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an apparatus for implementing a first method of the present invention.

FIG. 2 is a control flowchart of FIG. 1;

FIG. 3 is an overall configuration diagram showing an apparatus for implementing a second method of the present invention.

FIG. 4 is a control flowchart of FIG. 3;

FIG. 5 is a timing chart of the number of rotations of an exhaust blower and the concentration of dust, illustrating the control mode of FIG. 3;

FIG. 6 is a view corresponding to FIG. 1 for explaining a conventional method.

[Explanation of symbols]

 D, D1 ... Distance from the face d ... Diameter of the exhaust pipe K: Face L ... Length of the exhaust pipe S ... Dust sensor T ... Tunnel 1 ...・ Air blower 2 ・ ・ ・ Air blower tube 3 ・ ・ ・ Exhaust blower 4 ・ ・ ・ Exhaust air tube 10 ・ ・ ・ Dust sensor 11,11A ・ ・ ・ Control device 12,13 ・ ・ ・ Inverter

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuki Kikuchi 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Motohisa Okamoto 1-2-2 Moto-Akasaka, Minato-ku, Tokyo No. 7 Inside Kashima Construction Co., Ltd. (72) Inventor Inayaya Yokota 2-9-1 Tobita Sei, Chofu-shi, Tokyo Kashima Construction Co., Ltd. 19-1 Kashima Construction Co., Ltd.Technical Research Institute (72) Inventor Shoji Noma 2-7-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Yoichiro Nakamura Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (Chapter 2-7) Kajima Construction Co., Ltd. (72) Inventor Kajima Construction Co., Ltd. 1-2-7 Moto Akasaka, Minato-ku, Tokyo (72) Inventor Takaya Matsumoto Minato-ku, Tokyo 1-2-7 Akasaka, Kashima Construction Co., Ltd. (72) Inventor Takeshi Uki 1-5-1, Moto-Akasaka, Minato-ku, Tokyo Inside Fuji Kain Building Kajima Mechatronics Engineering Co., Ltd. (72) Inventor Masaaki Sato Tokyo 1-5-5 Moto-Akasaka, Minato-ku, Tokyo Fuji-in Building Kajima Mechatronics Engineering Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) E21F 1/00

Claims (2)

(57) [Claims] 1. A dust concentration sensor is arranged behind an area to be surely evacuated away from a face, and a diameter and a material corresponding to a diameter of an air supply and exhaust air tube, a tunnel excavation length are measured. Calculate the pressure loss of the wind pipe, calculate the exhaust air volume per unit time and the operation time required for the dust concentration detected by the dust concentration sensor to sufficiently clear the set reference value, A method for controlling the amount of ventilation air, wherein the number of rotations of the blower is controlled so that the dust concentration does not rise above a set reference value. 2. A dust concentration sensor is disposed behind an area to be surely evacuated away from the face, and based on a signal from the dust concentration sensor, when the dust concentration reaches a set abnormal value,
The exhaust blower is operated with the rotation speed at the maximum, and even if the dust concentration falls below the set abnormal value, the overrunning operation is continued for a certain time to reliably exhaust the dust, and after the overrunning operation is completed,
A ventilating air volume control method comprising performing normal operation control according to a set reference value of a dust concentration.