JP6664194B2 - Coal heating prediction management system - Google Patents

Description

  The present invention relates to a coal temperature rise prediction management system.

  In recent years, as the price of high-grade coal that has been used for a long time as coal for power generation in Japan has soared, movement to introduce low-grade coal such as bituminous coal and sub-bituminous coal has been activated.

  Generally, coal is stored in an open storage facility or a storage facility using silos. In any of the storage facilities, if the storage period becomes long, spontaneous ignition occurs.

  Conventionally, the coal storage period for avoiding spontaneous ignition is generally determined based on empirical values.However, since the low-grade coal easily ignites spontaneously, the coal storage facility is more than the case of the high-grade coal. It is necessary to strengthen the measures to prevent spontaneous combustion in Japan.

  As measures to prevent spontaneous ignition of the coal storage facility, for example, installing a gas detector so as to detect spontaneous ignition or using an anti-heating agent is performed. Measures such as watering and cooling have been taken in advance, and many studies have been made.

  In addition, there exists patent document 1 as an example which shows the general technical level relevant to the spontaneous ignition of low-grade coal.

JP 2014-126541 A

  However, when trying to determine the storage period of low-grade coal from empirical values, it was not possible to set an appropriate management temperature for coal of a new coal type, making it difficult to correctly determine the storage period. .

  In addition, the installation of a gas detector and the use of a temperature-raising inhibitor are enormous costs and labor, and in particular, the temperature-raising inhibitor may lead to a decrease in the quality of coal, and cannot be said to be a preferable measure. Was.

  On the other hand, even with coal of the same coal type, the rate of temperature rise of the coal may greatly change depending on the storage amount, the outside air temperature, the storage mode such as open storage or silo. For example, even if coal of the same coal type is stored, a fire may occur in one storage facility but not in another. In addition, spontaneous ignition takes a long time (several days to several tens of days) until the phenomenon occurs, has poor reproducibility, and effectively uses the data even when the time required for spontaneous ignition to be determined by actual measurement. I couldn't do that.

  In addition, uniform measures, such as cooling of coal by sprinkling water at coal storage facilities, which are currently being taken as measures to prevent spontaneous combustion, cannot be said to be management that is tailored to the type of coal and the form of storage of coal. Room was left.

  The present invention has been made in view of the above-mentioned conventional problems, and provides a coal temperature rise prediction management system capable of appropriately performing management so as to prevent spontaneous ignition in advance according to the coal type and storage form of coal being stored. It is something to offer.

The present invention is a coal analyzer for measuring the physical properties of coal stored in a coal storage facility,
A coal temperature rise simulation device for performing a numerical analysis based on the physical properties of the coal measured by the coal analysis device and information on the coal storage facility to obtain a temperature rise characteristic of the coal,
The temperature rise characteristic of the coal determined by the coal temperature rise simulation device is configured to be fed back from a simulation contractor to a storage manager of the coal storage facility ,
The coal analyzer,
A first analysis unit for supplying powdered coal as a sample by classifying the stored coal and measuring a low-temperature oxidation reaction rate from the powdered coal,
A second analysis unit for measuring the specific heat and water content from the bulk coal supplied with the bulk coal as a sample by processing the stored coal into a bulk,
A third analysis unit for processing the stored coal into a lump and supplying a lump coal as a sample and measuring the thermal conductivity from the lump coal;
The present invention relates to a coal temperature rise prediction management system characterized by comprising:

  The information of the coal storage facility may be at least one of the outside air temperature and the coal internal temperature, the shape of the coal seam, and the amount of stored coal.

  In the coal heating simulation apparatus, the low-temperature oxidation reaction rate, the specific heat, the water content, the thermal conductivity, and at least one of the outside air temperature and the coal internal temperature are input as information indicating input conditions. The shape of the coal seam and the amount of stored coal may be input as information indicating a coal analysis area.

  The coal heating simulation apparatus numerically analyzes the information indicating the input condition and the information indicating the analysis region with a computational fluid dynamics model in consideration of gas flow, chemical reaction, and heat transfer, and as an analysis result, stores coal. The temperature rise characteristics of the coal may be derived by calculating temperature, oxygen concentration, water content, air flow rate, and pressure, and repeatedly calculating the elapsed time.

  The coal analyzer and the coal heating simulator may be wirelessly connected.

  ADVANTAGE OF THE INVENTION According to the coal temperature rise prediction management system of this invention, the outstanding effect that management can be appropriately performed so that spontaneous ignition is prevented beforehand according to the coal type and storage form of the coal under storage can be produced.

1 is an overall schematic configuration diagram showing an embodiment of a coal temperature rise prediction management system of the present invention. It is a figure showing a coal analysis device in an example of a coal heating prediction management system of the present invention. FIG. 4 is a diagram illustrating a relationship between a temperature measured by a first analysis unit and an oxygen consumption in the embodiment of the coal temperature rise prediction management system of the present invention. (A) is a diagram showing the relationship between the temperature measured by the second analysis unit and the amount of heat in the embodiment of the coal heating prediction management system of the present invention, and (b) is a diagram of the coal heating prediction management system of the present invention. FIG. 5 is a diagram illustrating a relationship between a time measured by a second analysis unit, a sample temperature, and a sample weight in an example. It is a diagram which shows the relationship between the time measured by the 3rd analysis unit and the low temperature part temperature and high temperature part temperature in the Example of the coal temperature rise prediction management system of this invention. It is an analysis flow figure showing an example of a coal temperature rise prediction management system of the present invention. It is a figure which shows the shape of the coal layer in the Example of the coal temperature rise prediction management system of this invention, (a) is a figure which shows an example in which the shape of a coal layer is convex, (b) is a coal layer FIG. 4 is a diagram showing an example in which the shape of a circle is concave. FIG. 3 is a diagram showing the relationship between the storage days and the control temperature in a coal storage test silo manufactured to verify the embodiment of the coal temperature rise prediction management system of the present invention in the form of comparison between measured values and numerical analysis results. FIG. 4 is a temperature distribution diagram showing the temperature distribution of coal in a coal storage test silo manufactured for the purpose of verifying the embodiment of the coal temperature rise prediction management system of the present invention, by comparing measured values with numerical analysis results.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 9 show an embodiment of the coal temperature rise prediction management system of the present invention.

  In the case of the present embodiment, as shown in FIG. 1, a coal analyzer 1 for measuring physical properties of coal stored in a coal storage facility, and information on the physical properties of the coal measured by the coal analyzer 1 and the information on the coal storage facility. A coal temperature rise simulation device 2 for performing a numerical analysis based on the temperature rise characteristics of the coal. Then, the temperature rise characteristics of the coal obtained by the coal temperature rise simulation device 2 are converted from a simulation contractor (including a computer of the simulation contractor) to a storage manager of the coal storage facility (including a computer of the storage manager). ) To provide feedback. The storage manager is a power generation company or the like as a requestor having a coal storage facility. The contents of the temperature rise characteristics of the coal fed back to the storage manager are a graph (see FIG. 8) showing the relationship between the coal storage period and the temperature, and information on the recommended management temperature.

  As shown in FIG. 2, the coal analyzer 1 includes a first analysis unit 10, a second analysis unit 20, and a third analysis unit 30.

  The first analysis unit 10 includes a first heating furnace 13 having a built-in heater 11 and being surrounded by a heat insulating material 12 and having a controllable heating rate, A tubular reaction vessel 14 set in the reaction vessel 14, an air circulating device 15 for circulating air to the pulverized coal filled in the reaction vessel 14, An oxygen sensor 16 for measuring the oxygen concentration in the circulated air. In the first analysis unit 10, the reaction vessel 14 filled with pulverized coal is set in the first heating furnace 13, and the pulverized coal filled inside the reaction vessel 14 is supplied from the air circulation device 15. The temperature of the reaction vessel 14 is raised at a constant rate by the heater 11 while flowing air through the heater 11, and the oxygen concentration in the air that has passed through the pulverized coal is measured by the oxygen sensor 16. Is to be asked. Incidentally, the relationship between the temperature and the oxygen consumption is, for example, as shown in FIG. 3, from which the activation energy term and the constant term can be obtained. The pulverized coal is a sample obtained by classifying coal stored in a coal storage facility.

The second analysis unit 20 includes a second heating furnace 23 having a built-in heater 21 and surrounded by a heat insulating material 22 and having a controllable heating rate. The heater 21 of the second heating furnace 23 is supplied from a power source 24. A watt hour meter 25 for measuring the amount of electric power, a lump coal thermometer 26 for measuring the temperature of the lump coal set inside the second heating furnace 23, and a weigh scale 27 for measuring the weight of the lump coal. It has. As the weighing scale 27, a load cell, a balance, or the like can be used. In the second analysis unit 20, the lump coal is set in the second heating furnace 23, heat is applied to the lump coal by the heater 21 to increase the temperature, and the lump coal is converted into lump coal based on the electric energy measured by the watt hour meter 25. The given amount of heat Q is obtained. Further, at this time, the weight of the lump coal is measured by the weighing scale 27 to obtain the mass m, and the temperature change Δt of the lump coal is measured by the lump coal thermometer 26, and the specific heat C is calculated as C = Q / (m × Δt …… (1)
However, Q: calorie [J]
m: mass [g] (converted from weight)
Δt: temperature change [K]
It is becoming more demanding. Here, the temperature and the amount of heat have, for example, a linear relationship as shown in FIG. After the measurement of the specific heat C, when the temperature of the lump coal is raised to 100 ° C. or higher, moisture evaporates, and, for example, as shown in FIG. 4B, the temperature of the lump coal as a sample increases with time. On the other hand, since the weight of the lump coal decreases, the moisture content is determined from the change in weight of the lump coal after the temperature rise. The lump coal is obtained by processing coal stored in a coal storage facility into lump and making it into a sample, and the size of the lump coal is about 30 to 50 mm.

The third analysis unit 30 includes a third heating furnace 33 which has a built-in heating plate 31, is surrounded by a heat insulating material 32, and has a controllable heating rate. Further, a watt-hour meter 35 for measuring the amount of power supplied from the power supply 34 to the heating plate 31 of the third heating furnace 33 is set inside the third heating furnace 33 with its upper surface exposed to the outside. the bottom side of the lumped carbonaceous high-temperature portion temperature T and the high-temperature portion temperature gauge _{36 H} to measure, the third upper side of the lumped carbonaceous that is set inside the heating furnace 33 (the side facing the heating plate 31) (external and a low-temperature portion temperature meter 37 for measuring the low-temperature portion temperature T _C on the side) to be exposed to. In the third analysis unit 30, lump coal processed so that the cross-sectional area S is constant and the length (height) is L is exposed inside the third heating furnace 33 on the upper surface side. set by the heating plate 31 heats the bottom side of the lumped carbonaceous, top side open, as shown in FIG. 5, so that the high-temperature portion temperature T _H of the bottom side of the lumped carbonaceous becomes constant after reaching a predetermined temperature The amount of power is adjusted, and the heat flow q given to the lump coal is obtained based on the amount of power measured by the watt-hour meter 35. Furthermore, to measure the temperature difference ΔT of lumped carbonaceous at this time (= T H _{-T C)} at a high temperature portion temperature gauge 36 and the low temperature portion thermometer 37, the thermal conductivity of the steady state λ λ = (q / S) / (ΔT / L) (2)
Here, q: heat flow [W]
S: sectional area [m ² ]
ΔT: temperature difference [K]
L: Length [m]
It is becoming more demanding.

  As shown in FIG. 6, the information on the coal storage facility includes at least one of the outside air temperature and the coal internal temperature, the shape of the coal seam, and the amount of stored coal. The shape of the coal layer is, for example, a convex shape as shown in FIG. 7A, or a concave shape as shown in FIG. 7B. FIG. 7 shows a case where the coal storage facility is a silo 50. The upper portion of the silo 50 is open, and an opening for discharging coal is formed at the bottom thereof. Due to natural convection, air flows in from the bottom of the silo 50, and air containing gas released from the stored coal passes through an empty space above the silo 50 and flows out from the upper end to the outside. ing.

  As shown in FIG. 6, the coal heating simulation apparatus 2 receives the low-temperature oxidation reaction rate, the specific heat, the water content, the thermal conductivity, and at least one of the outside air temperature and the coal internal temperature. Information indicating conditions is input, and the shape of the coal seam and the amount of stored coal are input as information indicating an analysis area of coal.

  Further, as shown in FIG. 6, the coal heating simulation apparatus 2 compares the information indicating the input conditions and the information indicating the analysis area with a computational fluid dynamics (CFD) in consideration of gas flow, chemical reaction, and heat transfer. : Computational Fluid Dynamics) Numerical analysis with a model, the coal storage temperature, oxygen concentration, water content, air flow rate, and pressure are obtained as analysis results, and the temperature rise characteristics of the coal are derived by repeatedly calculating the passage of time. It has become.

  The coal analyzer 1 and the coal heating simulator 2 are wirelessly connected. However, since it is sufficient that the analysis result from the coal analysis device 1 can be used for the simulation of the coal heating simulation device 2, the coal analysis device 1 and the coal heating simulation device 2 do not necessarily need to be wirelessly connected.

  Next, the operation of the above embodiment will be described.

  First, the physical properties of coal stored in a coal storage facility are measured by the coal analyzer 1.

  The reaction vessel 14 of the first analysis unit 10 of the coal analyzer 1 is filled with pulverized coal which is a sample obtained by classifying coal stored in a coal storage facility, and the reaction vessel 14 filled with the pulverized coal. Is set inside the first heating furnace 13. In the first analysis unit 10, after the reaction vessel 14 filled with pulverized coal is set in the first heating furnace 13, the pulverized coal filled inside the reaction vessel 14 is supplied from the air circulation device 15. Air is circulated. In a state where air is circulated, the reaction vessel 14 is heated by the heater 11, the temperature of the reaction vessel 14 rises at a constant temperature rising rate, and the oxygen concentration in the air that has passed through the pulverized coal is measured by the oxygen sensor 16. Is done. At this time, the relationship between the temperature and the oxygen consumption is, for example, as shown in FIG. 3, and the low-temperature oxidation reaction rate is obtained from this relationship.

  In the second heating furnace 23 of the second analysis unit 20 of the coal analyzer 1, a lump of coal, which is a sample obtained by processing coal stored in a coal storage facility into lump, is set. In the second analysis unit 20, the lump coal is heated by the heater 21 and rises in temperature. The amount of heat Q given to the lump coal is calculated based on the amount of power measured by the watt hour meter 25. At this time, the weight of the lump coal is measured by the weigh scale 27 to obtain the mass m, and the temperature change Δt of the lump coal is measured by the lump coal thermometer 26. Here, the temperature and the amount of heat have, for example, a linear relationship as shown in FIG. 4A, and the specific heat C of the lump coal is calculated from the above equation (1) (C = Q / (m × Δt)). Desired. Further, after the measurement of the specific heat C, when the temperature of the lump coal is raised to 100 ° C. or higher, the water evaporates. For example, as shown in FIG. Since the weight of the lump coal decreases while it rises, the water content is determined from the weight change of the lump coal after the temperature rise.

In the third heating furnace 33 of the third analysis unit 30 of the coal analysis apparatus 1, lump coal processed to have a constant cross-sectional area S and a length (height) L is set to the third heating furnace 33. Set it with the top side exposed to the outside inside. In the third analysis unit 30, the bottom side of the lump coal is heated by the heating plate 31, and the upper side is open. As shown in FIG. 5, the temperature of the bottom side of the lump coal (high-temperature portion temperature _TH ) is reduced. After reaching the predetermined temperature, the electric energy is adjusted so as to be constant, and the heat flow q given to the lump coal is obtained based on the electric energy measured by the electric energy meter 35. Temperature difference ΔT of lumped carbonaceous at this time (= T H _{-T C)} is measured at a high temperature portion temperature gauge 36 and the low temperature portion temperature gauge 37, the thermal conductivity of the steady-state lambda is the equation (2) (λ = ( q / S) / (ΔT / L)).

  The coal analyzer 1 outputs the low-temperature oxidation reaction rate, the specific heat, the water content, and the thermal conductivity as physical properties of the coal.

  On the other hand, as shown in FIG. 6, at least one of the outside air temperature and the coal internal temperature is measured as the information of the coal storage facility, and the shape of the coal layer is convex as shown in FIG. Alternatively, as shown in FIG. 7 (b), it is confirmed whether or not it is concave, and further, the amount of stored coal is measured. In addition, in the case of the silo 50 as a coal storage facility shown in FIG. 7, the upper part of the silo 50 is open, and an opening for discharging coal is formed at the bottom, so that natural convection due to a rise in the temperature of coal is caused. Accordingly, air flows in from the bottom of the silo 50, and air containing gas released from the stored coal passes through an empty space above the silo 50 and flows out from the upper end.

  Then, as shown in FIG. 6, the low-temperature oxidation reaction rate, the specific heat, the water content, the thermal conductivity, and at least one of the outside air temperature and the coal internal temperature are information indicating input conditions, While being input to the coal heating simulation device 2 wirelessly connected to the coal analysis device 1, the shape of the coal layer and the amount of stored coal are input to the coal heating simulation device 2 as information indicating an analysis area. .

  In the coal heating simulation apparatus 2, as shown in FIG. 6, the information indicating the input condition and the information indicating the analysis area are numerically expressed by a computational fluid dynamics model in consideration of gas flow, chemical reaction, and heat transfer. The temperature is analyzed, and as a result of the analysis, the coal storage temperature, oxygen concentration, water content, air flow rate, and pressure are obtained, and the temperature rise characteristics of the coal are derived by repeatedly calculating the elapsed time.

  As shown in FIG. 1, the temperature rise characteristics of the coal obtained by the coal temperature rise simulation device 2 are fed back from a simulation contractor to a storage manager of the coal storage facility.

  The storage manager of the coal storage facility, based on the temperature rise characteristics of the coal (for example, a graph showing the relationship between the coal storage period and the temperature (see FIG. 8) and information on the recommended management temperature) fed back from the simulation contractor, Can be managed.

  Incidentally, the present inventors manufactured a 120-ton scale coal storage test silo to demonstrate this example, and compared the relationship between the storage days and the control temperature in the coal storage test silo with measured values and numerical analysis results. Was done. The experimental results are as shown in FIG. 8, and it was confirmed that the numerical analysis results substantially coincided with the actually measured values. In the case of the example shown in FIG. 8, it is determined from the numerical analysis result that the number of storage days is 125 days and the temperature of the stored coal reaches the control temperature (for example, 60 [° C.]). It can be seen that there is almost no error.

  Further, when an experiment was performed to compare the temperature distribution of coal in the coal storage test silo with the actually measured values and the numerical analysis results, as shown in FIG. 9 after 45 days and 50 days, the numerical analysis results were substantially the same as the actually measured values. It was confirmed that they matched.

  That is, in the case of the present embodiment, unlike the case of determining the coal storage period of low-rank coal from empirical values, it is possible to set an appropriate management temperature for coal of a new coal type, and to determine the coal storage period correctly. Becomes possible.

  Also, as a measure for preventing the occurrence of spontaneous ignition of the coal storage facility, it is not necessary to install a gas detector so as to detect spontaneous ignition or to use an anti-heating agent, so that a great deal of cost and labor are not required. At the same time, it is possible to avoid a decrease in the quality of coal due to the use of the temperature rise inhibitor.

  On the other hand, even with coal of the same coal type, the rate of temperature rise of the coal may vary greatly depending on the storage amount, the outside air temperature, open storage or silo storage mode. The temperature rise characteristics of the coal determined by the temperature simulation device 2 are highly reliable, and the data can be effectively used.

  It is very effective in managing coal according to coal type and storage mode, unlike the current measures taken to prevent spontaneous ignition, such as cooling of coal by watering at coal storage facilities. Becomes

  In the case of the present embodiment, the coal stored in the silo as the coal storage facility is shown in FIGS. 7 and 9, but it is needless to say that the present invention can be applied to a case where the coal storage facility is stacking coal. .

  In this way, management can be appropriately performed so as to prevent spontaneous ignition in accordance with the type of coal and the storage form of the coal being stored.

  The coal analysis apparatus 1 is provided with a first analysis unit 10 for supplying powdered coal as a sample by classifying the stored coal and measuring a low-temperature oxidation reaction rate from the powdered coal, and a stored coal. Is processed into a lump and a lump of coal is supplied as a sample, and the second analysis unit 20 for measuring specific heat and water content from the lump of coal, and lump of coal is sampled by processing the stored coal into lump is supplied. And a third analysis unit 30 for measuring thermal conductivity from the lump coal. Thereby, the physical properties of the coal stored in the coal storage facility can be accurately and efficiently measured.

  The information on the coal storage facility includes at least one of the outside air temperature and the coal internal temperature, the shape of the coal seam, and the amount of stored coal. This makes it possible to accurately grasp the factors that have a large effect in obtaining the temperature rise characteristics of the coal, thereby improving reliability.

  Further, the coal temperature raising simulation apparatus 2 is configured to provide information indicating that the low-temperature oxidation reaction rate, the specific heat, the water content, the thermal conductivity, and at least one of the outside air temperature and the coal internal temperature indicate input conditions. And the shape of the coal seam and the amount of stored coal are input as information indicating an analysis area of coal. This clarifies the input conditions and the analysis area, respectively, and helps to improve the accuracy of the simulation.

  Further, the coal heating simulation apparatus 2 numerically analyzes the information indicating the input conditions and the information indicating the analysis region using a computational fluid dynamics model in consideration of gas flow, chemical reaction, and heat transfer, and analyzes the results. The temperature rise characteristics of the coal are derived by calculating the coal storage temperature, oxygen concentration, water content, air flow rate, and pressure, and repeatedly calculating the elapsed time. As a result, even when compared with the actually measured values, it is possible to obtain the temperature rise characteristics of the coal with the error being minimized, which is extremely effective in preventing spontaneous ignition of the coal.

  Furthermore, since the coal analysis device 1 and the coal temperature raising simulation device 2 are wirelessly connected, even if the coal storage facility is located at a remote location, the simulation contractor can use the sample provided by the storage manager as the requester. It is possible to easily collect the physical properties of coal based on and accumulate data.

  In addition, the coal temperature rise prediction management system of the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Coal analyzer 2 Coal heating simulation device 10 First analysis unit 20 Second analysis unit 30 Third analysis unit

Claims (5)

A coal analyzer that measures the physical properties of coal stored in the coal storage facility,
A coal temperature rise simulation device for performing a numerical analysis based on the physical properties of the coal measured by the coal analysis device and information on the coal storage facility to obtain a temperature rise characteristic of the coal,
The temperature rise characteristic of the coal determined by the coal temperature rise simulation device is configured to be fed back from a simulation contractor to a storage manager of the coal storage facility ,
The coal analyzer,
A first analysis unit for supplying powdered coal as a sample by classifying the stored coal and measuring a low-temperature oxidation reaction rate from the powdered coal,
A second analysis unit for measuring the specific heat and water content from the bulk coal supplied with the bulk coal as a sample by processing the stored coal into a bulk,
A third analysis unit for processing the stored coal into a lump and supplying a lump coal as a sample and measuring the thermal conductivity from the lump coal;
Coal heating prediction management system characterized by comprising a. The coal storage facility information includes at least one of the outside air temperature and coal internal temperature, the shape of the coal layer, coal storage amount and the coal heating prediction management system of claim 1, wherein in at. In the coal heating simulation apparatus, the low-temperature oxidation reaction rate, the specific heat, the water content, the thermal conductivity, and at least one of the outside air temperature and the coal internal temperature are input as information indicating input conditions. The coal temperature rise prediction management system according to claim 2 , wherein the shape of the coal seam and the amount of stored coal are input as information indicating an analysis area of coal. The coal heating simulation apparatus numerically analyzes the information indicating the input condition and the information indicating the analysis region with a computational fluid dynamics model in consideration of gas flow, chemical reaction, and heat transfer, and as an analysis result, stores coal. The coal temperature rise prediction management system according to claim 3 , wherein the temperature, oxygen concentration, water content, air flow rate, and pressure are obtained, and the temperature rise characteristic of the coal is derived by repeatedly calculating the passage of time. The coal temperature rise prediction management system according to any one of claims 1 to 4 , wherein the coal analysis device and the coal temperature rise simulation device are wirelessly connected.

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