Fuel storage system and temperature estimation method

Abstract

The system accurately detects temperature increases due to fuel heat generation within the storage tank while minimizing the decrease in the amount of stored fuel. [Solution] The fuel storage system according to the present invention comprises a storage tank in which fuel is stored, a sensor provided in close proximity to the storage tank for detecting a predetermined substance, a supply unit capable of supplying a predetermined amount of capsules in which the predetermined substance is enclosed in an outer shell material that melts at a predetermined temperature to the storage tank, and an estimation unit which estimates that the temperature inside the storage tank is above a predetermined temperature when the sensor detects the predetermined substance leaking out to the outside as the outer shell material melts from the capsule.

Description

Technical Field

[0001] The present invention relates to a fuel storage system and a temperature estimation method.

Background Art

[0002] As an invention for detecting ignition of solid fuel used as fuel in a gasifier, boiler, etc. in a storage tank, there is, for example, a capsule disclosed in Patent Document 1. This capsule includes a tank portion into which a cooling gas is press-fitted, a temperature sensor for detecting temperature, a valve for discharging the cooling gas in the tank portion, and a wireless module for transmitting the operation status of the valve. This capsule is buried in a storage tank by being put in a plurality of pieces together with fuel such as biomass. When the fuel generates heat due to fermentation or natural oxidation and the temperature rises, and the temperature detected by the temperature sensor exceeds a set value, the valve operates to discharge the cooling gas in the tank portion. Since the temperature rise of the fuel around the capsule is suppressed by the cooling gas, spontaneous ignition of the fuel can be avoided. Further, the wireless module transmits the operation status of the valve and the position information of the capsule to a data processing terminal. The data processing terminal aggregates the transmitted operation status of the valve and the position information, and grasps the temperature distribution in the storage tank.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The capsule disclosed in Patent Document 1 is expected to be several tens of centimeters in size, for example, in order to house sufficient cooling gas to prevent fuel ignition, as well as temperature sensors, wireless modules, etc. However, if multiple capsules of this size are to be evenly distributed among the fuel in a storage tank, a problem may arise in that the amount of fuel that can be stored in the storage tank itself will decrease due to the large volume of the capsules. Furthermore, when the fuel is discharged from the storage tank, equipment is required to recover the capsules to prevent them from being fed into the boiler along with the fuel. If the capsules are recovered and reused, equipment for recovering the capsules, inspection of the recovered capsules, and a machine to return the capsules to the fuel after inspection are required, which will increase the equipment cost. In addition, when the capsules are put into the storage tank or discharged from the storage tank along with the fuel, there is a risk that sensors, valves, and wireless modules may malfunction due to impact, causing problems with the discharge of cooling gas and communication functions, and potentially preventing normal operation.

[0005] The present invention has been made in view of the above, and aims to accurately detect the temperature rise due to the heat generation of fuel in a storage tank while suppressing a decrease in the amount of fuel stored. [Means for solving the problem]

[0006] The fuel storage system according to the present invention comprises a storage tank in which fuel is stored; a sensor provided adjacent to the storage tank for detecting a predetermined substance; a supply unit capable of supplying a predetermined amount of capsules in which the predetermined substance is enclosed in an outer shell material that melts at a predetermined temperature to the storage tank; and an estimation unit that estimates that the temperature inside the storage tank is above a predetermined temperature when the sensor detects the predetermined substance leaking out to the outside as the outer shell material melts from the capsule.

[0007] The fuel storage system according to the present invention may also have a notification unit that notifies the outside if the estimation unit estimates that the temperature inside the storage tank is above the specified temperature.

[0008] In the fuel storage system according to the present invention, the supply unit may be capable of supplying the capsules containing the odor substance as the predetermined substance to the storage tank.

[0009] In the fuel storage system according to the present invention, the supply unit may include a first supply unit that supplies a first capsule containing a first predetermined substance as the predetermined substance and formed of an outer shell material having a melting point of the first predetermined temperature as the predetermined temperature, and a second supply unit that supplies a second capsule containing a second predetermined substance as the predetermined substance, wherein at least one of the first predetermined substance and the first predetermined temperature is different, and formed of an outer shell material having a melting point of the second predetermined temperature.

[0010] In the fuel storage system according to the present invention, the supply unit may introduce the first capsule and the second capsule into the storage tank at different timings.

[0011] The temperature estimation method according to the present invention comprises the steps of: supplying a predetermined amount of capsules, each capsule containing a predetermined substance enclosed in an outer shell material that melts at a predetermined temperature, to a storage tank in which fuel is stored; detecting the predetermined substance with a sensor provided in close proximity to the storage tank and which detects the predetermined substance; and estimating that the temperature inside the storage tank is above a predetermined temperature when the sensor detects the predetermined substance leaking out of the capsule due to the melting of the outer shell material. [Effects of the Invention]

[0012] According to the present invention, the temperature rise due to the heat generated by the fuel in the storage tank can be accurately detected while suppressing a decrease in the amount of fuel stored. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a schematic diagram of a fuel storage system according to an embodiment of this system. [Figure 2] Figure 2 is a schematic diagram showing the configuration of a microcapsule according to the embodiment. [Figure 3]Figure 3 is a block diagram showing the configuration of the monitoring device. [Figure 4] Figure 4 is a schematic diagram of a modified fuel storage system. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described in detail below with reference to the attached drawings. However, the present invention is not limited to the embodiments described below. Furthermore, in the drawings, the same or corresponding elements are appropriately denoted by the same reference numerals. It should also be noted that the drawings are schematic, and the dimensional relationships of each element may differ from those in reality. Even between drawings, there may be parts where the dimensional relationships and ratios differ.

[0015] Figure 1 is a schematic diagram of a fuel storage system 1 according to an embodiment of the present invention. The storage tank 20 is a steel storage tank for storing fuel F of a power plant (not shown). The fuel F stored in the storage tank 20 is, for example, biomass fuel such as wood pellets or PKS (Palm Kernel Shell). Note that the fuel F is not limited to wood pellets or PKS, but may also be RPF (Refuse derived paper and plastics densified fuel), a fuel-based molded product, compressed pulverized coal, or coal. The storage tank 20 is, for example, cylindrical in shape. The storage tank 20 has an inlet 21 at its upper end into which the fuel F and microcapsules 2 (described later) are introduced. The storage tank 20 also has a cutting device 22 at its lower end for cutting out the fuel F stored inside. The fuel F cut out by the cutting device 22 is transported by a belt conveyor 43 to a boiler (not shown) of the power plant.

[0016] The fuel transport line 41 is a transport route for transporting fuel F to the storage tank 20. The fuel transport line 41 includes a belt conveyor and a bucket elevator. For example, fuel F unloaded from a ship by an unloader is fed into the fuel transport line 41 and transported to the storage tank 20.

[0017] The capsule transport line 42 is a transport route that uses compressed air to transport the microcapsules 2 stored in a tank (not shown). The microcapsules 2 transported by the capsule transport line 42 are sent to the cyclone 31.

[0018] The cyclone 31 is located at the top of the capsule tank 32. The cyclone 31 separates the microcapsules 2 that are sent in with the air. The microcapsules 2 separated by the cyclone 31 are stored in the capsule tank 32. The capsule tank 32 is a tank for temporarily storing the microcapsules 2 in order to quantitatively extract them. The capsule tank 32 is located above the storage tank 20. A rotary feeder 33 is provided at the bottom of the capsule tank 32. The rotary feeder 33 supplies the microcapsules 2 stored in the capsule tank 32 to the input port 21. The capsule tank 32 and the rotary feeder 33 are examples of a supply unit according to the present invention.

[0019] Figure 2 is a schematic diagram showing the structure of the microcapsule 2. The microcapsule 2 has a diameter of several micrometers to several thousand micrometers and consists of a core material 3a, which is a predetermined substance detectable by a sensor described later, and an outer shell 3b. The core material 3a is, for example, aqueous ammonia, but is not limited to this. The outer shell 3b is formed of, for example, a paraffin-based compound that melts above a predetermined temperature, and encloses the core material 3a so that it does not leak out of the capsule below that predetermined temperature. The thickness of the outer shell 3b is, for example, in the range of 0.1% to 10% of the diameter of the microcapsule 2. The thickness and material of the outer shell 3b are selected so that it melts at a temperature of, for example, 60°C or higher, and the core material 3a inside leaks out to the outside. When the outer shell 3b melts, the microcapsule 2 releases the core material 3a.

[0020] The sensor 40 is an odor sensor that detects an odor substance, which is a predetermined substance enclosed by the outer shell 3b within the capsule, that is, the odor substance of the core substance 3a. For example, it is a sensor disclosed in Japanese Patent Application Laid-Open No. 2024-57731. The sensor 40 is disposed at the upper end within the storage tank 20. The sensor 40 has a film that adsorbs the odor substance, and detects the mass change that occurs when the odor substance, which is a volatile chemical substance that can be smelled by people or the sensor, adsorbs onto the film surface as a change in the frequency of a crystal oscillator, and converts the change value into numerical data. The numerical data converted by the sensor 40 is transmitted to the monitoring device 10. Here, although the sensor 40 detects the odor substance, it may not be limited to the detection of the odor substance, but may also detect the concentration of a substance or the wavelength specific to the substance.

[0021] Figure 3 is a block diagram showing the configuration of the monitoring device 10. The monitoring device 10 is a device that monitors the temperature of the fuel F. The monitoring device 10 includes a control unit 100, an operation unit 101, and a display unit 102. The operation unit 101 has a keyboard, a mouse, and various buttons for operating the monitoring device 10, and is operated by an operator. The display unit 102, which is an example of the notification unit according to the present invention, is, for example, a liquid crystal display device, and displays information related to the detection result of the sensor 40.

[0022] The control unit 100 includes an arithmetic unit and a storage unit. The arithmetic unit is composed of, for example, a CPU (Central Processing Unit). The storage unit includes a part composed of, for example, a ROM (Read Only Memory) and a part composed of a RAM (Random Access Memory). Programs, data, etc. used by the arithmetic unit for arithmetic processing are stored in the part composed of the ROM. The RAM is used to store a work space when the arithmetic unit performs arithmetic processing, the results of the arithmetic processing of the arithmetic unit, etc. The control unit 100, which is an example of the estimation unit according to the present invention, realizes the function of detecting, by means of the sensor 40, the odor substance of the core substance 3a that has melted from the outer shell 3b of the microcapsule 2 and leaked out of the microcapsule 2, and detecting the temperature rise in the storage tank 20 based on the numerical data transmitted from the sensor 40, by the CPU executing the program stored in the ROM.

[0023] Next, an example of the operation when storing the fuel F in the storage tank 20 will be described. The fuel F is conveyed by the fuel conveyance line 41 and sent to the inlet 21. When the fuel F is being sent to the inlet 21, the microcapsules 2 stored in the capsule tank 32 are supplied to the inlet 21 by the rotary feeder 33. The fuel F conveyed to the inlet 21 falls into the storage tank 20 together with the microcapsules 2 supplied from the rotary feeder 33 to the inlet 21. The supply amount of the microcapsules 2 supplied by the rotary feeder 33 is, for example, a few percent with respect to the supply amount of the fuel F introduced into the storage tank 20. By supplying the microcapsules 2 with the rotary feeder 33 to the fuel F conveyed to the inlet 21, the microcapsules 2 are evenly positioned inside the storage tank 20.

[0024] Next, an example of the operation of the monitoring device 10 will be described. If the temperature of the fuel F in the storage tank 20 is below the temperature at which the outer shell 3b melts, the core material 3a is not released from the microcapsule 2. In this state, the odor molecules of the core material 3a do not reach the sensor 40, so the sensor 40 does not transmit numerical data corresponding to the odor of the core material 3a. If the control unit 100 does not transmit numerical data corresponding to the odor of the core material 3a from the sensor 40, it will, for example, display a message on the display unit 102 indicating that there is no abnormality in the temperature in the storage tank 20.

[0025] On the other hand, if the temperature of the fuel F rises above the melting temperature of the outer shell 3b of the microcapsule 2 due to fermentation of the fuel F in the storage tank 20, the outer shell 3b melts and the core material 3a leaks into the storage tank 20. The odorant substances of the core material 3a are carried to the top of the storage tank 20 by convection caused by the heat generated by the fuel F. The odorant substances that have flowed to the top of the storage tank 20 are detected by the sensor 40. The sensor 40 transmits numerical data corresponding to the detected odorant substances of the core material 3a to the monitoring device 10.

[0026] The control unit 100 acquires numerical data transmitted from the sensor 40. The control unit 100 estimates from the numerical data corresponding to the odor substance of the ammonia water, which is the core material 3a, that the temperature inside the storage tank 20 is above a specified temperature, and notifies the operator by displaying a warning message on the display unit 102 that the temperature inside the storage tank 20 is rising. The specified temperature here is a temperature that the control unit 100 has set in advance as a temperature above the melting temperature at which the outer shell 3b of the microcapsule 2 melts, and is a set temperature that is appropriately determined depending on the capacity of the storage tank 20, the amount of fuel to be stored, etc. Therefore, the melting temperature may equal the specified temperature, or it may be a temperature that has risen considerably above the melting temperature.

[0027] As described above, according to this embodiment, in the storage tank 20, core material 3a is released from the microcapsules 2 due to a temperature rise that is a precursor to ignition of the fuel F. The sensor 40 detects the odorant of this released core material 3a, and the monitoring device 10 outputs a message warning that the temperature in the storage tank 20 is rising according to the detection result of the sensor 40, thus notifying the precursor to ignition of the fuel F. In addition, in this embodiment, the diameter of the microcapsules 2 stored in the storage tank 20 together with the fuel F is small, ranging from a few micrometers to several thousand micrometers, and the microcapsules 2 fit into the gaps between the particles of the fuel F, so that the amount of fuel F stored in the storage tank 20 does not decrease. Furthermore, since the microcapsules 2 can be cut out from the storage tank 20 together with the fuel F and transported to the boiler by a belt conveyor 43 for combustion, there is no need to recover them like the capsules disclosed in Patent Document 1, thus reducing the effort of recovery and the cost increase of equipment. Furthermore, in this embodiment, since the microcapsule 2 does not have the sensors, valves, and communication modules that are present in the capsule disclosed in Patent Document 1, there is no risk of malfunction, and the precursors to fuel F ignition can be detected with high accuracy. In addition, in this embodiment, the number of devices to be inspected can be reduced compared to the embodiment in Patent Document 1.

[0028] [Differentiation] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above and can be implemented in various other forms. For example, the present invention may be implemented by modifying the embodiments described above as follows. The embodiments described above and the following modifications may be combined with each other. The present invention is also included in configurations that appropriately combine the components of each embodiment and each modification described above. Furthermore, further effects and modifications can be easily derived by those skilled in the art. Therefore, broader embodiments of the present invention are not limited to the embodiments and modifications described above, and various modifications are possible.

[0029] In the embodiment described above, only one type of microcapsule 2 is supplied to the storage tank 20, but multiple types of microcapsules 2 may be supplied to the storage tank 20. Figure 4 is a schematic diagram of a modified fuel storage system 1A. The fuel storage system 1A includes cyclones 31a, 31b, 31c, capsule tanks 32a, 32b, 32c, and rotary feeders 33a, 33b, 33c. The capsule tanks 32a, 32b, 32c and the rotary feeders 33a, 33b, 33c are examples of supply units according to the present invention.

[0030] The capsule transport line 42a is a transport route that pumps microcapsules 2a stored in a tank (not shown). The microcapsules 2a pumped by the capsule transport line 42a are sent to the cyclone 31a. The microcapsules 2a separated from the air by the cyclone 31a are stored in the capsule tank 32a. The capsule tank 32a is a tank for temporarily storing microcapsules 2a in order to quantitatively dispense them. The capsule tank 32a is equipped with a rotary feeder 33a at its bottom. The rotary feeder 33a supplies the microcapsules 2a stored in the capsule tank 32a to the input port 21.

[0031] The capsule transport line 42b is a transport route that pumps microcapsules 2b stored in a tank (not shown). The microcapsules 2b pumped by the capsule transport line 42b are sent to the cyclone 31b. The microcapsules 2b separated from the air by the cyclone 31b are stored in the capsule tank 32b. The capsule tank 32b is a tank for temporarily storing microcapsules 2b in order to quantitatively dispense them. The capsule tank 32b is equipped with a rotary feeder 33b at its bottom. The rotary feeder 33b supplies the microcapsules 2b stored in the capsule tank 32b to the input port 21.

[0032] The capsule transport line 42c is a transport route that pumps microcapsules 2c stored in a tank (not shown). The microcapsules 2c pumped by the capsule transport line 42c are sent to the cyclone 31c. The microcapsules 2c separated from the air by the cyclone 31c are stored in the capsule tank 32c. The capsule tank 32c is a tank for temporarily storing microcapsules 2c in order to quantitatively dispense them. The capsule tank 32c is equipped with a rotary feeder 33c at its bottom. The rotary feeder 33c supplies the microcapsules 2c stored in the capsule tank 32c to the input port 21. In Figure 4, the piping from rotary feeders 33a, 33b, and 33c merge and connect to the input port 21, but they may be connected to the input port 21 separately without merging.

[0033] Microcapsule 2a has an outer shell 3b that melts at a temperature of 70°C or higher. The core material 3a of microcapsule 2a is ammonia water, the same as in microcapsule 2. Microcapsule 2b has an outer shell 3b that melts at a temperature of 80°C or higher. The core material 3a of microcapsule 2b is, for example, an aqueous acetone solution. Microcapsule 2c has an outer shell 3b that melts at a temperature of 90°C or higher. The core material 3a of microcapsule 2a is, for example, acetic acid. The melting temperature of the outer shell 3b of microcapsules 2a, 2b, and 2c is adjusted by the thickness and material of the outer shell 3b.

[0034] In the configuration shown in Figure 4, when fuel F is being supplied to the inlet 21, microcapsules 2a are supplied to the inlet 21 by the rotary feeder 33a, microcapsules 2b are supplied to the inlet 21 by the rotary feeder 33b, and microcapsules 2c are supplied to the inlet 21 by the rotary feeder 33c.

[0035] When the fuel F ferments in the storage tank 20 and its temperature reaches 70°C, the temperature at which the outer shell 3b of the microcapsule 2a melts, ammonia water, which is the core material 3a, is released from the microcapsule 2a. The odorant of the ammonia water, which is the core material 3a, that flows to the top of the storage tank 20 is detected by the sensor 40. The sensor 40 transmits numerical data corresponding to the odorant to the monitoring device 10.

[0036] The control unit 100 acquires numerical data transmitted from the sensor 40. Based on the numerical data corresponding to the odor substances in the ammonia water, the control unit 100 estimates that the temperature inside the storage tank 20 has reached 70°C and displays a message on the display unit 102 indicating that the temperature inside the storage tank 20 has reached 70°C.

[0037] Furthermore, as the temperature of the fuel F in the storage tank 20 rises to 80°C or higher, causing the outer shell 3b of the microcapsules 2b to melt, the core material 3a, which is an aqueous acetone solution, is released from the microcapsules 2b. The odorant in the aqueous acetone solution, which is the core material 3a, that flows to the top of the storage tank 20 is detected by the sensor 40. The sensor 40 transmits numerical data corresponding to the odorant to the monitoring device 10.

[0038] The control unit 100 acquires numerical data transmitted from the sensor 40. Based on the numerical data corresponding to the odor substances in the acetone aqueous solution, the control unit 100 estimates that the temperature inside the storage tank 20 has reached 80°C and displays a message on the display unit 102 indicating that the temperature inside the storage tank 20 has reached 80°C.

[0039] Furthermore, when the temperature of the fuel F in the storage tank 20 rises to 90°C or higher, causing the outer shell 3b of the microcapsules 2c to melt, acetic acid, which is the core material 3a, is released from the microcapsules 2c. The odorant of the acetic acid, which is the core material 3a, that flows to the top of the storage tank 20 is detected by the sensor 40. The sensor 40 transmits numerical data corresponding to the odorant to the monitoring device 10.

[0040] The control unit 100 acquires numerical data transmitted from the sensor 40. Based on the numerical data corresponding to the acetic acid odor substance, the control unit 100 estimates that the temperature inside the storage tank 20 has reached 90°C and displays a message on the display unit 102 indicating that the temperature inside the storage tank 20 has reached 90°C. According to this modified configuration, it is possible to detect a rise in temperature inside the storage tank 20 and notify of the precursor to ignition of fuel F.

[0041] In the configuration shown in Figure 4, the capsule tanks 32a, 32b, and 32c may be configured to transport microcapsules 2 having the same melting temperature of the outer shell 3b, but with different core materials 3a. For example, the core material 3a of the microcapsules 2 transported to capsule tank 32a may be ammonia water, the core material 3a of the microcapsules 2 transported to capsule tank 32b may be acetic acid, and the core material 3a of the microcapsules 2 transported to capsule tank 32c may be acetone aqueous solution.

[0042] When supplying fuel F to the lower layer of the storage tank 20, microcapsules 2 in which the core material 3a is ammonia water are supplied to the storage tank 20 from capsule tank 32a by rotary feeder 33a. When supplying fuel F to the middle layer of the storage tank 20, microcapsules 2 in which the core material 3a is acetic acid are supplied to the storage tank 20 from capsule tank 32b by rotary feeder 33b. When supplying fuel F to the upper layer of the storage tank 20, microcapsules 2 in which the core material 3a is acetone aqueous solution are supplied to the storage tank 20 from capsule tank 32c by rotary feeder 33c.

[0043] When fuel F ferments or oxidizes in the lower layer of storage tank 20, and the temperature of fuel F exceeds the melting temperature of the outer shell 3b of microcapsule 2, ammonia water, which is the core material 3a, is released from the microcapsule 2 in the lower layer of storage tank 20. When fuel F ferments or oxidizes in the middle layer of storage tank 20, and the temperature of fuel F exceeds the melting temperature of the outer shell 3b of microcapsule 2, acetic acid, which is the core material 3a, is released from the microcapsule 2 in the middle layer of storage tank 20. When fuel F ferments or oxidizes in the upper layer of storage tank 20, and the temperature of fuel F exceeds the melting temperature of the outer shell 3b of microcapsule 2, aqueous acetone solution, which is the core material 3a, is released from the microcapsule 2 in the upper layer of storage tank 20.

[0044] When the sensor 40 detects an odorant in ammonia water, it transmits numerical data corresponding to the odorant in ammonia water to the monitoring device 10. When it detects an odorant in acetic acid, it transmits numerical data corresponding to the odorant in acetic acid to the monitoring device 10. When it detects an odorant in acetone aqueous solution, it transmits numerical data corresponding to the odorant in acetone aqueous solution to the monitoring device 10.

[0045] If the numerical data acquired from the sensor 40 corresponds to the odor substance of ammonia water, the control unit 100 will display a message on the display unit 102 warning that the temperature is rising in the lower layer of the storage tank 20. If the numerical data acquired from the sensor 40 corresponds to the odor substance of acetic acid, the control unit 100 will display a message on the display unit 102 warning that the temperature is rising in the middle layer of the storage tank 20. If the numerical data acquired from the sensor 40 corresponds to the odor substance of acetone aqueous solution, the control unit 100 will display a message on the display unit 102 warning that the temperature is rising in the upper layer of the storage tank 20. This modified version makes it possible to detect where in the storage tank 20 the temperature is rising.

[0046] In this invention, microcapsules 2 may be placed in an adhesive coating agent, the microcapsules 2 together with the coating agent may be sprayed onto the fuel F, and the fuel F to which the microcapsules 2 have adhered due to the coating agent may be supplied to the storage tank 20. As the coating agent, a highly viscous fluid such as polyacrylic acid or sodium polyacrylate with a molecular weight of more than 100,000, corn syrup, edible glue, or mucin is preferred. With this modification, the distance between the fuel F and the microcapsules 2 is short, and the microcapsules 2 adhering to the heated fuel F melt immediately, thus shortening the time until a temperature rise in the storage tank 20 can be detected.

[0047] In the embodiment described above, the sensor 40 is located at the upper end of the storage tank 20. However, the location of the sensor 40 is not limited to the location in the embodiment and may be in other locations. For example, the sensor 40 may be located in the middle and lower parts of the storage tank 20, in addition to the upper end.

[0048] In the embodiment described above, the microcapsules 2 and fuel F are mixed at the inlet 21, but the location where the microcapsules 2 are mixed with the fuel F is not limited to the inlet 21, but may be at other locations. For example, the microcapsules 2 may be mixed with the fuel F at a location along the fuel transport line 41 or at the upstream end of the fuel transport line 41 in the transport direction. Also, if the microcapsules 2 are mixed with the fuel F upstream of the inlet 21 in the transport direction of the fuel F, one or more sensors 40 may be placed at multiple locations between the inlet 21 and the upstream end of the fuel transport line 41 in the transport direction. According to this modification, it is possible to detect the temperature rise of the fuel F before it enters the storage tank 20.

[0049] The core material 3a is not limited to a liquid, but may also be a gas. Furthermore, the core material 3a is not limited to ammonia water, acetic acid, acetone aqueous solution, etc., but may also be other substances or gases.

[0050] In the present invention, the sensor 40 is not limited to a sensor that detects the odor of the core material 3a, but may be a sensor that detects the core material 3a. Furthermore, the sensor 40 may also define the core material 3a as the concentration of a gas detectable by, for example, a gas detector. In this modified example, when the sensor 40 detects the core material 3a, it transmits data indicating that the core material 3a has been detected to the monitoring device 10. When the control unit 100 of the monitoring device 10 receives this data, it displays a message on the display unit 102 warning that the temperature inside the storage tank 20 is rising. [Explanation of Symbols]

[0051] 1. 1A Fuel Storage System 2, 2a, 2b, 2c Microcapsules 3a Core material 3b Outer shell 10 Monitoring equipment 20 Storage tanks 32, 32a, 32b, 32c Capsule Tanks 33, 33a, 33b, 33c Rotary feeder 40 sensors 100 Control Unit

Claims

1. A storage tank where fuel is stored, A sensor for detecting a predetermined substance is installed adjacent to the storage tank, A supply unit capable of supplying a predetermined amount of capsules, each containing a predetermined substance enclosed in an outer shell material that melts at a predetermined temperature, to the storage tank, A fuel storage system comprising: an estimation unit that estimates that the temperature inside the storage tank is above a specified temperature by detecting the predetermined substance that has leaked out of the capsule as the outer shell material has melted from the capsule.

2. The fuel storage system according to claim 1, further comprising a notification unit that notifies the outside when the estimation unit estimates that the temperature inside the storage tank is above the specified temperature.

3. The fuel storage system according to claim 1, wherein the supply unit is capable of supplying the capsules containing the odor substance as the predetermined substance to the storage tank.

4. The supply unit includes a first supply unit that supplies a first capsule containing a first predetermined substance as the predetermined substance and formed of an outer shell material having a melting point of the first predetermined temperature as the predetermined temperature, and a second supply unit that supplies a second capsule containing a second predetermined substance as the predetermined substance and formed of an outer shell material having a melting point of the second predetermined temperature, A fuel storage system according to claim 1, having the following:

5. The fuel storage system according to claim 4, wherein the supply unit puts the first capsule and the second capsule into the storage tank at different timings.

6. The steps include supplying a predetermined amount of capsules, each containing a predetermined substance encased in an outer shell material that melts at a predetermined temperature, to a storage tank where fuel is stored, A step of detecting the predetermined substance using a sensor provided in close proximity to the storage tank and which detects the predetermined substance, When the sensor detects the predetermined substance that has leaked out of the capsule due to the melting of the outer shell material, the sensor estimates that the temperature inside the storage tank is above a specified temperature. A temperature estimation method comprising the following features.

Images