JP2011140341A - Monitoring system and monitoring method for boiling over - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitoring system for boiling over which enables estimation of occurrence of boiling over with a simple configuration and which is easy to use, and to provide a monitoring method for boiling over. <P>SOLUTION: Strip-shaped heat-sensitive material 17 are provided from an upper part 7 to a lower part 9 of the sidewall 5 of a floating roof tank 1 storing petroleum 21, such as crude oil or heavy oil. The heat-sensitive material 17 are provided in four areas of the side wall 5 of the tank at every 90° pitch, as viewed from above. Each heat-sensitive material 17 has such a width that a change in the color of the heat-sensitive material 17 is visible from the outside of the break-oil 19 of the tank 1. In the event of fire of the whole tank, a change in the color of each of the temperature indicating material 17 is monitored, and the position and moving speed of the high temperature layer 27 in the tank 1 are estimated, and thereby occurrence of boiling over is monitored and estimated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a monitoring system and a monitoring method for monitoring and predicting the occurrence of boil-over during a full-scale fire of a tank that stores crude oil, heavy oil, and the like.

  In refineries and thermal power plants, large floating roof tanks are widely used to store oil such as crude oil and heavy oil. FIG. 5 is a cross-sectional view showing a basic configuration of a conventional floating roof tank 1. The tank 1 is provided in a state where the oil 21 is stored in the cylindrical tank body 3 and the metal floating roof 13 is stored in the stored oil 21.

  The floating roof 13 has a structure that can move following the vertical movement of the liquid level 23 of the oil 21. In order to prevent the oil 21 from leaking and evaporating, the sealing material 15 is provided on the outer peripheral portion so as to contact the inner surface of the tank body 3. Is provided. This prevents the oil 21 from leaking, but if a large force is applied to the floating roof 13 or the sealing material 15 due to an earthquake or the like, the oil 21 may leak from the seal portion and a fire may occur. The Tokachi-oki earthquake that occurred in September 2009 caused damage and sinking of the floating roof 13 due to the liquid level vibration of oil 21, causing a ring fire in the refinery crude oil tank and a full fire in the naphtha tank. Yes. Although it is possible to extinguish a ring fire with the existing fire extinguishing equipment, it is not easy to extinguish with the existing fire extinguishing equipment when the large floating roof tank 1 causes a full fire. For this reason, several fire extinguishing equipment and fire extinguishing methods corresponding to the entire fire have been proposed (see, for example, Patent Document 1 and Patent Document 2).

  When a full-scale fire occurs in the floating roof type tank 1, a high temperature region (hereinafter referred to as a high temperature layer) is formed in the tank 1, and this high temperature layer comes into contact with the water 25 accumulated at the bottom of the tank 1. It is pointed out that the water 25 suddenly boils and becomes steam, so-called boil-over that blows off the oil 21 at the top occurs, and there is a danger of causing a great deal of secondary damage in the vicinity. In order to monitor and predict the occurrence of boil-over, it is necessary to measure the temperature of the oil 21 in the tank 1 and monitor the occurrence and movement of the high temperature layer. For example, using an infrared thermometer, the temperature of the side wall surface 5 of the tank 1 (hereinafter, unless otherwise specified, the side wall surface refers to the outer surface of the side wall) is measured and stored in the tank 1 from this temperature. A method for estimating the temperature of the oil 21 and predicting the occurrence of boil-over is conceivable.

JP 2009-66348 A JP 2008-167800 A

  The method of monitoring and predicting the occurrence of boil-over by measuring the temperature of the tank side wall using an infrared thermometer requires preparation and adjustment work of the infrared thermometer, and this method requires prompt action. It is not suitable for such cases. In addition, it is necessary to approach a place where the temperature can be measured, which is a safety problem. Also, if you want to measure temperature from multiple directions for a large tank, it is necessary to prepare multiple measuring instruments, but it is a burden to have a measuring instrument that is infrequently used and perform daily inspections. Become.

  An object of the present invention is to provide a boilover monitoring system and a monitoring method capable of monitoring and predicting the occurrence of boilover that is easy to use with a simple configuration.

  The present invention is a boil-over monitoring system comprising a band-shaped temperature indicator from the upper part to the lower part of the outer surface of the side wall of a tank for storing a flammable liquid.

  Further, the present invention provides the boilover monitoring system, wherein the tank is provided with the temperature indicating material at four positions at a pitch of 90 ° on the outer side wall of the tank in a plan view, and the width of the temperature indicating material is determined by the oil-proofing of the tank. It is the width | variety which can visually recognize the change of the color of a temperature indicator from the outside.

  In the boilover monitoring system, the present invention further includes a monitoring camera capable of photographing the temperature indicating material, and an image analysis device for analyzing a temperature indicating material imaged by the monitoring camera and estimating a temperature distribution in the tank. And a display device for displaying a temperature distribution in the tank estimated by the image analysis device.

  Further, the present invention provides the boilover monitoring system further comprising an alarm device, wherein the image analysis device detects whether a predetermined temperature range in the tank has reached a predetermined height or a change over time in the predetermined temperature range. When it is predicted that the temperature range reaches a predetermined height within a predetermined time, a signal is sent to the alarm device to notify the danger of occurrence of boil-over.

  Further, the present invention provides a boilover monitoring method using the boilover monitoring system, wherein the temperature inside the tank is continued until the risk of occurrence of boilover disappears after the fire of the entire tank is extinguished. is there.

  The boilover monitoring system according to the present invention includes a band-shaped temperature indicator from the upper part to the lower part of the outer surface of the side wall of the tank that stores the flammable liquid. Therefore, the flammability in the tank is constantly and continuously detected from the color change of the temperature indicator. It is possible to estimate the temperature in the height direction of the liquid, and thus it is possible to monitor and predict the occurrence of boil-over. The temperature indicating material is an inexpensive monitoring system that is inexpensive and can be easily applied to existing tanks.

  Further, according to the present invention, the temperature indicating material is provided at four locations at a 90 ° pitch in plan view on the outer surface of the side wall of the tank, so that the temperature can be confirmed from a plurality of directions, and the occurrence of boil-over is predicted. Accuracy is improved. In addition, the temperature indicating material has a width that allows the color change of the temperature indicating material to be visually recognized from outside the tank oil barrier, so that more people can check the temperature at the same time from a safe place, making it easy to use. .

  According to the present invention, the boilover monitoring system according to the present invention further includes a monitoring camera capable of capturing the temperature indicating material, and an image for analyzing the temperature indicating image captured by the monitoring camera and estimating the temperature distribution in the tank. Since the analyzer and the display device that displays the temperature distribution in the tank estimated by the image analyzer are included, the occurrence of boilover can be monitored and predicted from a safer place.

  Further, according to the present invention, the boilover monitoring system according to the present invention further includes an alarm device, and the image analysis device is configured so that a predetermined temperature range in the tank reaches a predetermined height or a predetermined temperature range. When it is predicted that the temperature range will reach a predetermined height within a predetermined time from the change over time, a warning is issued to notify the danger of boil-over, so it is necessary in advance including evacuation etc. Can take a good response.

  Further, the boilover monitoring method according to the present invention can ensure sufficient safety since the temperature inside the tank is continuously monitored until the risk of occurrence of boilover disappears even after the fire of the entire tank is extinguished.

1 is a perspective view of a tank 1 according to a first embodiment of the present invention and provided with a temperature indicating material 17 on a side wall surface 5. FIG. It is a top view of the tank 1 of FIG. FIG. 2 is a broken sectional view for explaining a change in color of a temperature indicating material 17 when the tank 1 of FIG. It is a figure which shows schematic structure of the boilover monitoring system as 2nd Embodiment of this invention. It is sectional drawing which shows the basic composition of the conventional floating roof type tank 1. FIG.

  FIG. 1 is a perspective view of a tank 1 which is a first embodiment of the present invention and includes a temperature indicating material 17 on a side wall surface 5. FIG. 2 is a plan view of the tank 1 of FIG. FIG. 3 is a broken sectional view for explaining the color change of the temperature indicating material 17 when the tank 1 of FIG.

  The boil-over monitoring system according to the present invention measures the temperature of the side wall surface 5 of the tank 1 that stores oil 21 such as heavy oil and crude oil, and estimates the temperature of the oil 21 in the tank 1 from this, and boils the tank when the entire tank fires. This is a monitoring system for monitoring and predicting the occurrence of over, and a temperature indicating material 17 that changes color according to temperature is provided on the side wall surface 5 of the tank 1.

  The tank 1 is a cylindrical floating roof type tank having a floating roof 13 in the upper portion, and includes a temperature indicating material 17 on the side wall surface 5. The temperature indicating material 17 is provided on the side wall surface 5 of the tank in four strips at a pitch of 90 ° in plan view, from the upper part 7 to the lower part 11 of the side wall surface 5 of the tank 1. The width is such that the color change of the temperature indicating material 17 can be visually recognized from outside the oil supply 19.

  A known temperature indicating material can be used for the temperature indicating material 17. The temperature indicating material 17 changes its color irreversibly or reversibly due to melting or chemical change when it reaches a predetermined temperature, and is usually used in the form of paint or label. The temperature indicating material 17 can be easily provided on the side wall surface 5 of the tank 1 by applying a commercially available temperature indicating paint. The temperature of the temperature indicating material 17 is determined for each temperature indicating material. Here, the temperature indicating material 17 that changes color at a temperature of about 110 to 130 ° C. is preferable. The boil-over occurs when the high temperature layer 27 in the tank 1 comes into contact with the water 25 at the bottom of the tank. Since the high temperature layer 27 is said to have a temperature of about 200 to 250 ° C., the high temperature layer 27 can be detected by detecting this temperature. However, the temperature distribution in the tank 1, the temperature gradient, the side wall surface 5 of the tank 1. The temperature of the side wall surface 5 of the tank 1 to be detected can be detected at a temperature lower than the temperature of the high temperature layer 27 for safety, considering the difference between the surface temperature of the oil and the temperature of the internal oil 21 and the accuracy of the temperature indicator 17. Should. The tank 1 for storing the oil 21 is normally heated by a heating device for ensuring the fluidity of the oil 21 and facilitating transportation, but the temperature is about 60 ° C., and the temperature indicating material 17 Does not change color.

  Although the temperature indicating material 17 may be provided only at one location on the side wall surface 5, it is preferable to provide the temperature indicating material 17 at a plurality of locations so that the temperature indicating material 17 can be seen from the entire circumferential direction of the tank 1. By allowing many people, such as those engaged in fire fighting activities, to see at the same time, the occurrence of boil-over can be monitored and predicted more accurately. Since the boilover occurs when the high temperature layer 27 in the tank 1 comes into contact with the water 25 at the bottom of the tank 1, the boilover can be prevented by providing the temperature indicating material 17 only near the lower portion 11 of the side wall surface 5. Although monitoring and prediction are possible, considering the temperature error and the uncertainty of the water level of the water 25, the prediction accuracy is lacking. On the other hand, by providing the temperature indicating material 17 from the upper part 7 to the lower part 11 of the side wall surface 5 of the tank 1, it becomes possible to detect the movement of the high-temperature layer 27 in the tank height direction, and the occurrence of boilover with high accuracy. Can be monitored and predicted. For this reason, it is important to apply the temperature indicating material 17 from the upper part 7 to the lower part 11 of the side wall surface 5 of the tank 1. In addition, it goes without saying that the temperature indicating material 17 may be visually recognized through a surveillance camera, a telescope, etc. Usually, fire extinguishing activities are performed from outside the oil barrier 19, so it is easy for those engaged in fire extinguishing activities and the like. It is preferable that the width of the temperature indicator 17 is a width that allows the color change of the temperature indicator 17 to be easily visually recognized from the outside of the oil barrier 19.

  A method for monitoring the occurrence of boilover using the boilover monitoring system will be described. As seen in the Tokachi-oki earthquake, the floating roof type tank 1 may break down the floating roof 13 and sink into the tank body 3 when a large earthquake occurs. When the floating roof 13 sinks, the oil surface of the oil 21 is exposed to the atmosphere and the evaporated oil 21 comes into contact with the atmosphere. At this time, if a spark is generated due to static electricity or the like, a full-scale fire in which the evaporated oil 21 ignites and the upper surface of the tank 1 burns occurs.

  When a full-scale fire occurs in the tank 1, the upper part of the tank 1 is burning, so that the upper part 7 of the side wall surface 5 of the tank 1 easily exceeds the discoloration temperature of the temperature indicating material 17, and the temperature indicating material 17 changes color. Immediately after the occurrence of the fire, the temperature of the side wall surface 5 other than the upper portion 7 is close to the temperature of the stored oil 21 itself, and since the temperature is low, the temperature indicating material 17 is not discolored except for the upper portion 7 of the side wall surface 5.

  When a full-scale fire occurs, the high temperature layer 27 is formed by the heat from the flame 29. The high temperature layer 27 increases in thickness with time and further falls. Due to the descending of the high temperature layer 27, the intermediate portion 9 of the side wall surface 5 is also heated and the temperature rises, and the temperature indicating material 17 applied to the side wall surface 5 of the tank 1 changes in color from the upper portion 7 toward the lower portion 11. Since the color change speed corresponds to the descending speed of the high temperature layer 27, the position and descending speed of the high temperature layer 27 can be grasped from this. There is water 25 at the bottom of the tank 1, and when the high temperature layer 27 reaches the bottom of the tank 1 and comes into contact with the water 25, it causes a dangerous boilover that blows off the burning oil 21. Therefore, the time until the high temperature layer 27 reaches the water 25 accumulated at the bottom of the tank 1 due to the color change of the temperature indicating material 17 is estimated, and the fire extinguishing activity, cooling operation, etc. of the tank 1 are performed. Evacuate from the scene.

  Since the temperature of the high temperature layer 27 causing the boil-over is said to be about 200 to 250 ° C., the temperature of the temperature indicating material 17 is considerably higher than the temperature of about 110 to 130 ° C. at which the temperature indicating material 17 changes color. The position cannot be the position of the high temperature layer 27. Actually, it is assumed that the temperature indicating material 17 is at a position higher than the discoloration position. However, the temperature error of the temperature indicating material 17 and the temperature detected by the temperature indicating material 17 is the temperature of the outer surface of the side wall of the tank 1, and there is a temperature difference with the oil 21 inside, and the temperature distribution in the tank 1, Considering the temperature gradient and further safety, it is sufficiently possible to regard the lower end portion 18 of the discolored temperature indicating material 17 as the lower end portion 28 of the high temperature layer. Of course, a position slightly higher than the lower end portion 18 of the discolored temperature indicating material 17 may be the lower end portion 28 of the high temperature layer.

  It is important that monitoring of boil-over continues after the entire tank fire has been extinguished. Even if the entire tank fire is extinguished, the high temperature layer 27 exists in the tank 1 and these may expand or descend. For this reason, even after the entire tank fire is extinguished, the movement of the high temperature layer 27 is continuously monitored from the color change of the temperature indicating material 17, and the cooling operation of the tank 1 is performed as necessary, so that the high temperature layer 27 disappears or the high temperature layer 27 disappears. Monitoring should continue until it can be confirmed that the lowering and expansion of the layer 27 has completely stopped.

  In the above-described embodiment, an example in which the temperature indicating material 17 that changes color at a temperature of about 110 to 130 ° C. is used, but two types of temperature indicating material 17 that changes color at different temperatures, for example, a color that changes at a temperature of about 110 to 130 ° C. If the temperature indicating material and the temperature indicating material that changes color at a temperature of 200 ° C. are provided side by side, the temperature in the tank 1 can be detected more accurately.

  FIG. 4 is a diagram showing a schematic configuration of a boilover monitoring system as a second embodiment of the present invention. This boilover monitoring system is generally a system in which the boilover monitoring system of the first embodiment is automated. The same members as those in the boilover monitoring system according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Hereinafter, it is assumed that the temperature indicating material 17 is provided with a temperature indicating material whose color changes at a temperature of 110 ° C.

  In the boil-over monitoring system shown in the second embodiment, the temperature indicating material 17 provided on the side wall surface 5 of the tank 1 is imaged by the monitoring camera 31, and the image of the temperature indicating material 17 captured by the monitoring camera 31 is analyzed. The internal temperature is estimated and displayed on the display device 35, and the risk of occurrence of boil-over is notified via the alarm device 37 as necessary. The boilover monitoring system shown in the second embodiment is safe because the boilover can be monitored from a remote location.

  The surveillance camera 31 may be a portable camera or a fixed camera installed on the premises, and can photograph the color of the temperature indicating material 17 so that the color of the temperature indicating material 17 can be identified at least from the outside of the oil barrier 19 on the outer periphery of the tank 1. Any camera can be used. It is preferable to install four surveillance cameras 31 as many as the number of temperature indicating materials 17 provided in the tank 1 in the present embodiment from the viewpoint of improving the prediction accuracy of occurrence of boil-over. Only the material 17 may be monitored. The image taken by the monitoring camera 31 is sent to the image analysis device 33, where the image is processed and the temperature in the tank 1 is estimated.

  The image analysis device 33 can detect a region having a temperature of 110 ° C. or higher by analyzing the color of the temperature indicating material 17 taken by the monitoring camera 31. Since the color after the color change of the temperature indicating material 17 is known in advance, the temperature can be easily calculated by determining the color from the image captured by the monitoring camera 31. The image analysis device 33 sets a temperature obtained by adding a predetermined temperature, for example, 20 ° C., to the temperature calculated from the color change of the temperature indicating material 17 as the temperature in the tank 1. The image analysis device 33 processes the image taken by the monitoring camera 31 over time, enables the temporal change of the temperature distribution in the tank 1 to be displayed as a graph, and sends the data to the display device 35. Further, the image analysis device 33 estimates the position of the high temperature layer 27 and the descending speed from the temporal change of the temperature distribution in the tank 1 to estimate the time when the boil-over occurs. Here, the lower end portion 28 of the high temperature layer 27 may be regarded as the lower end portion 18 of the discolored temperature indicating material 17 as described in the first embodiment. Accordingly, the process proceeds in a safe direction, and the position of the high temperature layer 27 and the descending speed can be easily calculated. A detailed planar temperature distribution is obtained by image analysis of the discoloration of the four temperature indicating materials 17.

  The display device 35 displays the temperature distribution diagram in the tank 1 calculated by the image analysis device 33, the position of the high temperature layer 27, the descending speed, the time when the boilover occurs, and the like.

  Furthermore, the image analysis apparatus 33 determines whether the lower end 28 of the high temperature layer 27 in the tank 1 to be calculated has reached a predetermined height or the high temperature layer 27 within a predetermined time from a change with time of the lower end 28 of the high temperature layer 27. When it is predicted that the lower end portion 28 will reach a predetermined height, a signal is sent to the alarm device 37, and the alarm device 37 notifies the danger of occurrence of boil-over. Here, the predetermined height may be a position where a person engaged in fire extinguishing activities can evacuate with a margin, for example, a position about 1 to 2 m higher than the water accumulated at the bottom of the tank 1. Such an image analysis device 33 can be realized using a computer and a program.

  As described above, as shown in the first embodiment and the second embodiment, the boilover monitoring system according to the present invention is capable of constantly and continuously detecting the temperature in the height direction of the flammable liquid in the tank from the change in the color of the temperature indicating material. Furthermore, it is possible to predict the position of the high temperature layer and the descent speed, and it is possible to monitor and predict the occurrence of boilover safely with a simple configuration. It is also convenient because the entire tank fire can be continuously monitored after the fire is extinguished without the need for special equipment.

DESCRIPTION OF SYMBOLS 1 Tank 3 Tank main body 5 Tank side wall outer surface 7 Upper part of tank side wall outer surface 11 Lower part of tank side wall outer surface 17 Temperature indicator 19 Oil barrier 21 Oil 25 Water 27 High temperature layer 29 Flame 31 Monitoring camera 33 Image analysis device 35 Display device 37 Alarm apparatus

Claims (5)

  A boil-over monitoring system comprising a band-shaped temperature indicator from the upper part to the lower part of the outer side wall of a tank for storing a flammable liquid.   The tank is provided with the temperature indicator on the outer surface of the side wall of the tank at four positions at a 90 ° pitch in a plan view, and the temperature indicator width can be visually recognized from the outside of the tank oil barrier. The boilover monitoring system according to claim 1, wherein the boilover monitoring system has a wide width. Furthermore, a surveillance camera capable of photographing the temperature indicating material,
An image analysis device that analyzes an image of a temperature indicating material photographed by the monitoring camera and estimates a temperature distribution in the tank;
A display device for displaying a temperature distribution in the tank estimated by the image analysis device;
The boilover monitoring system according to claim 1 or 2, characterized by comprising: Furthermore, an alarm device is provided,
The image analysis apparatus predicts that the predetermined temperature range in the tank has reached a predetermined height, or that the temperature range reaches a predetermined height within a predetermined time from a change in the predetermined temperature range over time. 4. The boilover monitoring system according to claim 3, wherein a warning is given to the alarm device to notify the danger of occurrence of boilover. 5.   Using the boil-over monitoring system according to any one of claims 1 to 4, the temperature in the tank is continuously monitored until the risk of occurrence of boil-over disappears after the entire tank fire is extinguished. How to monitor boilover.

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