JPH0252817B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Technical Field of the Invention The present invention relates to a device for pre-monitoring spontaneous combustion of piled coal.

(2) Prior Art As shown in Fig. 1, the piled coal 1 has a trapezoidal cross section and is piled up in the shape of a mountain range. For example, it is a large one with a base length of 50m, a height of 17m, and a length of 500m.

The mechanism of spontaneous combustion is that on the verge of ignition, the temperature inside the coal pile is 80 to 90 degrees Celsius, 1 a.m.
It is known that the surface temperature increases by 2 to 3 degrees Celsius over 2 to 3 meters.

For this reason, conventionally, the entire side of the piled coal 1 was monitored in a two-dimensional manner using thermovision, etc., but with this method, the measurement accuracy was only about 2 to 3 degrees Celsius, making it impossible to predict or monitor spontaneous combustion. It was hot.

(3) Purpose of the Invention In view of the above points, the purpose of the present invention is to provide a spontaneous ignition monitoring device for piled coal that has a simple configuration and is capable of highly reliable monitoring of spontaneous ignition.

(4) Embodiment of the Invention FIG. 2 is a configuration explanatory diagram showing an embodiment of the invention.

In the figure, reference numeral 1 denotes open piled coal, and a radiation thermometer 21 installed along the longitudinal direction of a predetermined width on one side of the halfway point 1a is moved by a drive device (not shown) to the halfway point 1a.
The temperature at each point is measured by uniaxial forward scanning in the height direction including a predetermined width on one side of a. In addition, multiple radiation thermometers 2n are connected to open coal 1
These radiation thermometers 21, . . . , 2n are installed on a steel frame or the like that covers the piled coal 1 (not shown). 3 is
Calculate the output signals of the radiation thermometers 21,..., 2n,
This is a calculation device that generates alarm signals 41, .

Next, the operation will be explained with reference to FIG.

For example, considering one radiation thermometer 21, first, in one reciprocating scan of the middle part 1a of the piled coal 1, the average value of the temperature at each point as shown in FIG. In the next backward scan, the difference between this average value and the temperature at each point is compared as shown in Figure 3b, and when this difference exceeds a predetermined temperature, the temperature at that measurement point is calculated. An alarm signal 41 is generated as shown in FIG. 3c. This alarm signal 4
1, etc., to open the water sprinkler valves, etc., and extinguish the fire at the warning point of the piled coal 1. It should be noted that the illustration shows an object in which there was no alarm state at the time of forward scanning in FIG. 3a. Furthermore, even if an alarm state is included, the signals are averaged, so a slightly higher average value level is calculated as shown in FIG. 3b, and an alarm signal can be obtained as shown in FIG. 3c.

Similar operations are performed for other radiation thermometers, and the number of computing devices 3 may be one or more in total.

By doing this, even if there is a drift error in the radiation thermometer, the drift is removed by subtracting in the forward and backward scans, and it does not affect the measurement of temperature differences, thereby preventing spontaneous combustion. A difference of 2 to 3° C. between the average value of the forward scan and the temperature value of the backward scan for monitoring can always be sufficiently determined.

(5) Summary of the Invention Spontaneous combustion of piled coal is monitored by scanning the middle of the piled coal back and forth in the longitudinal direction with a radiation thermometer and comparing the average value of the forward scan and the temperature at each point of the backward scan. This is a spontaneous ignition monitoring device for piled coal.

(6) Effects of the invention By calculating the average value of each point in the forward scanning of a plurality of radiation thermometers installed on the middle of the coal pile and the temperature difference of each point in the backward scanning, this value is determined to be a predetermined value. Since it is calculated and monitored to see if it exceeds the value, even if there is an error such as drift in the radiation thermometer, it is completely canceled out and accurate monitoring is always possible. Furthermore, since the height direction of the piled coal is uniaxially scanned, scanning is simple, the cost is low, and the practical effect is great.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the principle, FIG. 2 is a diagram for explaining the configuration of an embodiment of the present invention, and FIG. 3 is a waveform diagram for explaining the operation. 1...Pile of coal, 1a...Middle slope, 21-2n...
...Radiation thermometer, 3...Arithmetic device, 41-4m...
alarm signal.

Claims (1)

[Claims] 1. A plurality of radiation thermometers scan multiple measurement points halfway up the longitudinal direction of the piled coal, each reciprocating along a single axis in the height direction, and the average value of the temperature at each scanning point is calculated using the forward scanning of each radiation thermometer. and an arithmetic device that compares the difference between this average value and the temperature at each point during backward scanning, and generates an alarm signal for that measurement point when this difference exceeds a predetermined temperature, and the alarm signal of this arithmetic device generates an alarm signal. A spontaneous ignition monitoring device for piled coal, characterized in that it extinguishes the fire at alarm points of piled coal.