Flood Sensor and Notification System

Abstract

This flooding sensor 1 comprises a notification unit 4 for providing a notification that flooding has been detected and a primary battery 3. The primary battery 3 comprises a positive electrode 33, a negative electrode 31, and a separator 35 that is disposed between the positive electrode 33 and negative electrode 31 and has an electrolyte 38 adhered thereto. When the separator 35 is submerged, the electrolyte 38 is dissolved in water so as to produce an electrolyte solution and the primary battery 3 starts producing electricity and supplies the electrical power necessary to drive the notification unit 4.

Description

[Technical field]

[0001] The present invention relates to a flood sensor and notification system. [Background technology]

[0002] Conventionally, alkaline batteries, manganese batteries, air batteries, etc. have been widely used as disposable primary batteries.

[0003] Furthermore, with the recent development of the Internet of Things (IoT), the development of scattered sensors that can be installed anywhere in nature, such as in soil or forests, is also progressing. Small, high-performance lithium-ion batteries that can be used for a variety of purposes, including these small sensors, are also becoming widespread.

[0004] One type of sensor that is installed outdoors is a flood sensor that uses a specific low-power radio (see Non-Patent Document 1). The flood sensor described in Non-Patent Document 1 detects water when the installation position is flooded to a specified height or higher, and notifies the user using an IoT wireless unit. In addition, a sensor network system that prepares for flooding or water damage has been proposed and a demonstration experiment is being conducted (see Non-Patent Document 2). In the sensor network system, various sensors such as those for water level, point flow velocity, and flap gate opening degree are used.

[0005] Generally, there are batteries that operate by injecting an electrolyte solution into the battery cell when in use (see Non-Patent Document 3). This battery can be stored for a long time without the electrolyte solution being injected. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] OPTEX Co., Ltd., "Quickly identify the risk of flooding and inundation with simple IoT monitoring", [online], [Retrieved March 17, 2021], Internet〈URL:https: / / www.optex.co.jp / solutions / flood_solution.html〉 [Non-Patent Document 2] Ministry of Land, Infrastructure, Transport and Tourism, "Sensor network system to prepare for flooding and flood damage", [online], [Retrieved March 17, 2021], Internet〈URL:https: / / www.mlit.go.jp / tec / i-construction / pdf / matching_180516_siryou_7.pdf〉 [Non-Patent Document 3] Nippon Kyono Electronics Co., Ltd., "NOPOPO Water-Resistance Battery for Disasters", [online], [Retrieved March 17, 2021], Internet〈URL:http: / / www.aps-j.jp / pdf / NWPx3.pdf〉 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the sensors described in Non-Patent Document 1 and Non-Patent Document 2 have mechanisms for detection and reporting that are constantly in operation, and require periodic replacement of internal batteries, etc. In Non-Patent Document 1, the flooding sensor itself has zero standby power, but the IoT wireless unit that reports flooding is powered by an internal battery.

[0008] The battery described in Non-Patent Document 3 is used by injecting an electrolyte solution into it. Therefore, the battery described in Non-Patent Document 3 is not capable of supplying power in situations where humans cannot be involved, such as when it is installed in the natural world.

[0009] In this way, there is no aspect in which power to be notified is supplied in response to detection by the sensor.

[0010] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a technique capable of supplying power for notification in response to detection by a sensor. [Means for solving the problem]

[0011] A flooding sensor of one embodiment of the present invention comprises a notification unit that notifies the detection of flooding, and a primary battery, the primary battery comprising a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode to which an electrolyte is adhered, and when the separator becomes flooded, the electrolyte dissolves in water to form an electrolyte solution, and the primary battery begins generating power to supply the power necessary to drive the notification unit.

[0012] A notification system of one embodiment of the present invention comprises the above-mentioned flooding sensor and a notification server connected to the flooding sensor and referring to the position and height of the flooding sensor, wherein a notification unit of the flooding sensor notifies of flooding of the flooding sensor, and the notification server determines the importance of an alarm depending on the position and height of the flooding sensor that notified of the flooding. Effect of the Invention

[0013] According to the present invention, it is possible to provide a technique that can supply power to notify when a flood sensor detects a flood. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic side view illustrating the internal structure of a submersion sensor according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating the system configuration of a notification system according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a flowchart illustrating the process of the notification server according to the embodiment of the present invention. [Figure 4] FIG. 4 is a diagram illustrating the change over time in the battery voltage of the primary battery in the flooded sensor according to the embodiment of the present invention. [Diagram 5]FIG. 5 is a schematic side view illustrating the internal structure of a submergence sensor according to a first modified example of the present invention. [Figure 6] FIG. 6 is a schematic side view illustrating the internal structure of a submersion sensor according to a second modified example of the present invention. [Figure 7] FIG. 7 is a diagram illustrating the hardware configuration of a computer used as the notification server. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the description of the drawings, the same parts are given the same reference numerals and the description will be omitted.

[0016] (Flood sensor) A flood sensor 1 according to an embodiment of the present invention will be described with reference to Fig. 1. The flood sensor 1 includes a housing 2, a primary battery 3, and a notification unit 4. The primary battery 3 includes a positive electrode 33, a negative electrode 31, and a separator 35 that is disposed between the positive electrode 33 and the negative electrode 31 and to which an electrolyte 38 is adhered.

[0017] In the flood sensor 1 according to the embodiment of the present invention, when the separator 35 in the primary battery 3 is flooded, the electrolyte 38 attached to the separator 35 dissolves in water to form an electrolyte solution. The electrolyte 38 diffuses with the water to generate an electrolytic solution, and the separator 35 is immersed in the electrolytic solution. This causes the primary battery 3 to start generating power and supply the power required to drive the notification unit 4. The notification unit 4 obtains the power and notifies the user that the sensor is flooded. In this way, the flood sensor 1 is driven by the primary battery 3 that generates power when the sensor is flooded, so that it does not need to be operated during normal times and can only notify the user of operation in an emergency. This allows the flood sensor 1 to be operated for a long period of time, such as for more than 10 years, without self-discharge when not in operation.

[0018] The primary battery 3 includes a basic cell 36 and a battery casing 37. The basic cell 36 includes a negative electrode 31, a negative electrode current collector 32, a positive electrode 33, a positive electrode current collector 34, and a separator 35. An air hole 39 is formed in the primary battery 3. Air is taken into the primary battery 3 through the air hole 39.

[0019] The separator 35 is formed to communicate with the outside in order to take in water when submerged and turn the electrolyte 38 into an electrolytic solution. For example, a part of the separator 35 is exposed from the battery housing 37 and communicates with the outside through an opening (not shown) in the housing 2, and takes in water when submerged. In order to prevent the separator from being submerged due to rain, snow, etc., it is preferable that the opening of the housing 2 is provided below the housing 2, more preferably on the bottom surface. In the example shown in FIG. 1, the separator 35 includes a main body portion housed in the battery housing 37 and a tape portion exposed from the battery housing 37. The tape portion of the separator 35 is also exposed from the housing 2 and takes in water when submerged.

[0020] As long as the negative electrode 31, the negative electrode current collector 32, the positive electrode 33, the positive electrode current collector 34, the separator 35, the battery casing 37, the electrolyte 38, and the air hole 39 can operate as a battery, there is no limitation on the arrangement and shape of each member. For example, the negative electrode 31, the negative electrode current collector 32, the positive electrode 33, the positive electrode current collector 34, the separator 35, and the battery casing 37 may be in the form of a rectangular or circular sheet in a plan view, or in the form of a rolled sheet.

[0021] A negative electrode 31 is connected to the negative electrode current collector 32. A positive electrode 33 is connected to the positive electrode current collector . A separator is disposed between the negative electrode 31 and the positive electrode 33. One surface of the positive electrode 33 is connected to the separator .

[0022] The negative electrode 31, the negative electrode current collector 32, the positive electrode 33, the positive electrode current collector 34, and the separator 35, which are connected to each other, are sandwiched vertically in a battery case 37, and the peripheral parts are bonded and integrated, thereby sealing the inside of the primary battery 3. The bonding method may be, but is not limited to, a method using heat sealing or an adhesive. For example, when bonding by heat sealing is difficult, an adhesive is used. When sealing the inside of the primary battery 3, an air hole 39 may be formed by leaving a part of the peripheral part open without bonding or leaving a hole. The air hole 39 allows air to be taken into the primary battery 3. The tape part of the separator 35 is formed so as to be exposed from the part of the peripheral part of the primary battery 3 that is not bonded and is open.

[0023] The positive electrode 33 is of a gas diffusion type. The surfaces of the positive electrode 33 other than the surface in contact with the separator 35 are exposed to the peripheral portion of the battery casing 37 or the air taken in through the air hole 39.

[0024] Separator 35 is made of a water-absorbent insulating material. Paper such as coffee filters and kitchen paper can be used for separator 35. If separator 35 is made of a sheet of a naturally decomposable material that maintains its strength, such as a cellulose-based separator made from plant fibers, the burden on the environment can be reduced even if flood sensor 1 is not collected after installation.

[0025] The electrolyte 38 may be an electrolyte solution when it absorbs water. Agar, cellulose, water-absorbing polymers, etc. may be enclosed to retain water.

[0026] The battery housing 37 may have any configuration as long as it can hold the basic cells 36 inside. To prevent the primary battery 3 from generating electricity due to the separator 35 becoming wet with rainwater or the like, it is preferable that the housing 2 and the battery housing 37 are configured to prevent rainwater or the like from penetrating into the inside of the battery housing 37. The battery housing 37 is preferably formed of, for example, a laminate film.

[0027] In addition, by using naturally degradable materials for the battery housing 37 and the housing 2, the burden on the environment is reduced even if the flooded sensor 1 is not recovered. Specifically, the battery housing 37 and the housing 2 are each formed from one or more of polylactic acid, polycaprolactone, polyhydroxyalkanoate, polyglycolic acid, modified polyvinyl alcohol, casein, modified starch, and the like. Among these, it is particularly preferable that the battery housing 37 and the housing 2 are each formed from a chemical synthesis system such as plant-derived polylactic acid. The shapes of the battery housing 37 and the housing 2 are shapes obtained by processing such biodegradable plastics. Materials that can be applied to the battery housing 37 and the housing 2 are, for example, one or more of biodegradable plastics, biodegradable plastic films, paper coated with a resin such as polyethylene used in milk cartons, and agar films.

[0028] When water comes into contact with separator 35 due to flooding, the water is taken up into separator 35 by capillary action. Electrolyte 38 in separator 35 dissolves in water and becomes an electrolyte solution. When the electrolyte solution thus produced comes into contact with negative electrode 31 and positive electrode 33, respectively, primary battery 3 starts generating power. Primary battery 3 supplies power to notification unit 4, which can notify that flooding sensor 1 has detected flooding.

[0029] The notification unit 4 notifies the detection of submergence. In the embodiment of the present invention, as shown in FIG. 3, a case will be described in which the notification unit 4 notifies the detection of submergence to the notification server 102 via a wireless communication network. The wireless communication network may be mobile communications provided by a mobile communication carrier, or a specific low-power radio that complies with standards such as ARIB (Association of Radio Industries and Businesses) STD-T67, STD-T93, or STD-T108. Another possible notification method is to light up a lamp (not shown) provided in the submergence sensor 1 when submergence occurs.

[0030] The notification unit 4 includes a power supply circuit 41, an arithmetic circuit 42, a communication circuit 43, and an antenna 44. The arithmetic circuit 42, the communication circuit 43, and the antenna 44 are each driven by power supplied from the primary battery 3 during flooding.

[0031] The power supply circuit 41 converts the power supplied from the primary battery 3 into a voltage that can be used by each circuit. The power supply circuit 41 is, for example, a DCDC (Direct Current to Direct Current) circuit. As shown in FIG. 1, the negative electrode current collector 32 and the positive electrode current collector 34 are connected to the power supply circuit 41. The power supply circuit 41 converts the power supplied from the negative electrode current collector 32 and the positive electrode current collector 34 into a desired voltage and provides it to each circuit of the notification unit 4.

[0032] The arithmetic circuit 42 generates data to be transmitted to the notification server 102, and inputs the data to the communication circuit 43. The transmission data includes the identification number of the submergence sensor 1.

[0033] The antenna 44 is an interface for connecting to a wireless communication network. The communication circuit 43 communicates with the notification server 102 using the antenna 44.

[0034] In the case of flooding occurring, flood sensor 1 according to the embodiment of the present invention generates power from primary battery 3 built into flood sensor 1, enabling notification by notification unit 4. Flood sensor 1 does not require operation under normal circumstances, and operates only in emergencies caused by the occurrence of flooding, and is able to notify the occurrence of flooding. This allows flood sensor 1 to operate for long periods of time, such as for more than 10 years, without self-discharge when not in use.

[0035] Each component of the flood sensor 1 can also be made from naturally degradable materials. Such a flood sensor 1 is suitable for use as a disposable sensor that is installed in nature, such as a flood detection sensor or a soil moisture sensor. The housing 2 and primary battery 3 used in the flood sensor 1 each naturally decompose over time, so there is no need to collect the flood sensor 1. Furthermore, because the flood sensor 1 is made from naturally derived materials and fertilizer components, it places an extremely low burden on the environment.

[0036] Furthermore, because flood sensor 1 according to an embodiment of the present invention has a configuration that enables primary battery 3 to be driven when flooded, it is possible to inexpensively and easily install flood sensor 1 outdoors and replace it after flooding. Also, considering that flood sensor 1 has the characteristic of having an extremely low environmental impact, it is possible to easily grasp the flooding situation by placing a large number of flood sensors 1 outdoors.

[0037] (Notification System) A notification system 100 according to an embodiment of the present invention will be described with reference to Fig. 2. In the notification system 100, a plurality of flood sensors 1 are arranged in various locations where flooding is likely to occur due to rainfall or the like.

[0038] The notification server 102 monitors and aggregates notifications from the flood sensor 1, identifies the location of the flood and the scale of the disaster, etc., and provides the information to a monitor such as a local government or administrative body. Note that the system configuration shown in Fig. 2 is one example, and may be modified as appropriate depending on the specifications of the wireless communication network, the location where the flood sensor 1 is installed, etc.

[0039] The notification system 100 includes a plurality of flood sensors 1, a base station 101, a notification server 102, a database server 103, and a transmitting device 104. The flood sensor 1 communicates with the notification server 102 via the base station 101.

[0040] The base station 101 is connected to the notification server 102 and is also connected wirelessly to the flooding sensor 1. The notification server 102 is connected to a plurality of flooding sensors 1 via the base station 101. The database server 103 stores the location where the flooding sensor 1 is installed and the height such as the altitude, and the notification server 102 can refer to the data stored in the database server 103. The height of the flooding sensor 1 is used to estimate the depth of flooding at the flooding sensor 1 when the flooding sensor 1 is notified that it is flooded. The transmission device 104 transmits an alarm according to the importance of the alarm in the notification server 102. The transmission device 104 is a device used by a supervisor of a local government or an administrative body in an existing alarm system, and transmits a warning or evacuation warning to residents. The transmission device 104 is an existing broadcasting facility such as a disaster prevention radio, an outdoor loudspeaker branch office, an emergency contact email transmission device, etc.

[0041] For example, the notification unit 4 of the flood sensor 1 notifies the notification server 102 that the flood sensor 1 is submerged by transmitting an identifier of the flood sensor 1. The notification server 102 connects to the database server 103 and refers to the installation position and height of each flood sensor 1 that has sent a notification. The notification server 102 determines the importance of the alarm according to the position and height of the flood sensor 1 that notified the flood.

[0042] The notification server 102 also determines the importance of the alarm according to the number of flood sensors 1 that notify the occurrence of flooding. The more flood sensors 1 that notify the occurrence of flooding, the wider the area in which a disaster such as flooding is expected to have occurred, so the higher the importance of the alarm will be, and vice versa.

[0043] The notification server 102 can also determine the importance of the alarm according to the amount of precipitation at the location where the flood sensor 1 is installed. The more the amount of precipitation, the higher the importance of the alarm, and the less the amount of precipitation, the lower the importance of the alarm.

[0044] The processing of the notification server 102 will be described with reference to Fig. 3. In the processing shown in Fig. 3, when a signal is received from a certain flood sensor 1, the alarm alert level is determined according to signals from other flood sensors 1, the amount of rainfall, etc., and notified to an existing alarm system. Note that the processing shown in Fig. 3 is one example and is not limited to this.

[0045] First, in step S1, the notification server 102 receives a signal from one submergence sensor 1 indicating that submergence has occurred, and then in step S2, waits for a predetermined time to receive signals from other submergence sensors 1. If no signal is received from another submergence sensor 1, the process proceeds to step S3, and if a signal is received from another submergence sensor 1, the process proceeds to step S7.

[0046] In step S3, notification server 102 identifies the location where flood sensor 1 that received a signal in step S1 is installed from database server 103 or the like, and acquires the amount of precipitation in the most recent specified time period in the area including that location from a weather server (not shown) or the like. If notification server 102 determines in step S4 that the amount of precipitation acquired in step S3 is not equal to or greater than a threshold, it acknowledges the occurrence of an early warning alarm in step S5. If notification server 102 determines in step S4 that the amount of precipitation acquired in step S3 is equal to or greater than a threshold, it acknowledges the occurrence of a warning alarm in step S6.

[0047] In step S7, if the number of signals received during standby in step S1 is equal to or greater than a threshold, notification server 102 assumes that flooding has occurred over a wide area. In step S7, notification server 102 estimates the flood height and determines whether the estimated flood height is equal to or greater than a threshold. Notification server 102 estimates the flood height in the area from the height at which each flood sensor 1 that notified flooding during standby in step S2 is installed, and also from the height at which each flood sensor 1 that does not notify flooding is installed. If notification server 102 determines in step S7 that the flood height is equal to or greater than the threshold, it acknowledges the occurrence of a major warning alarm in step S9. If notification server 102 determines in step S7 that the flood height is not equal to or greater than the threshold, it proceeds to step S8.

[0048] If notification server 102 determines in step S8 that the number of signals received during standby in step S1 is equal to or greater than the threshold, it acknowledges the occurrence of a major alert alarm in step S9. On the other hand, if notification server 102 determines in step S8 that the number of signals received during standby in step S1 is not equal to or greater than the threshold, it considers that the area of ​​flooding is limited, and so acknowledges the occurrence of a alert alarm in step S10.

[0049] When the occurrence of an alarm is recognized in step S5, S6, S9, or S10, the recognized alarm is notified to an existing alarm system. The existing alarm system notifies residents and the like via the transmission device 104 in accordance with a predetermined rule.

[0050] The response that the alert system takes in response to various types of warning alarms is set appropriately according to the monitor's operational policy. As an example, when an early warning alarm occurs, a warning advisory is sent to the monitor's management screen. When a warning alarm occurs, a warning advisory is sent to multiple monitors. When a major warning alarm occurs, an evacuation advisory is sent to residents via the transmission device 104. When a warning alarm occurs, a warning advisory is sent to residents via the transmission device 104.

[0051] Such a notification system 100 can identify the area where a disaster has occurred, its scale, etc., according to signals from multiple flood sensors 1, and notify an existing alarm system. The flood sensor 1 according to the embodiment of the present invention is supplied with power and notifies only when flooding occurs, making it easy to maintain and manage, and thus making it possible to install a large number of flood sensors 1. Furthermore, by forming the flood sensor 1 from a biodegradable material, no burden is placed on the natural environment even if the flood sensor 1 is not recovered.

[0052] (Primary battery structure and electrode reactions) Here, each component of the primary battery 3 will be described.

[0053] The negative electrode 31 is formed from a negative electrode active material. The negative electrode 31 is formed from one or more metals selected from magnesium, zinc, aluminum, and iron, or an alloy mainly composed of one or more metals selected from magnesium, zinc, aluminum, and iron. The negative electrode 31 may be formed by a general method, such as by forming a metal or alloy plate or foil into a predetermined shape.

[0054] The positive electrode 33 is formed of a conductive material such as a carbon material that is used for the positive electrode of a general metal-air battery. The positive electrode 33 can be produced by a known process such as forming carbon powder with a binder. In a primary battery, it is important to generate a large amount of reaction sites inside the positive electrode 33, so it is desirable for the positive electrode 33 to have a high specific surface area. When the positive electrode 33 is produced by forming carbon powder with a binder and pelletizing it, the binding strength between the carbon powder particles decreases when the specific surface area is increased, and the structure deteriorates, making it difficult for the positive electrode 33 to discharge stably, and the discharge capacity decreases. In contrast, for example, when the positive electrode 33 has a three-dimensional network structure, the positive electrode 33 does not need to use a binder, and the discharge capacity can be increased. In addition, the positive electrode 33 may support a catalyst. The catalyst is not particularly limited, but is preferably composed of at least one metal selected from Fe, Mn, Zn, Cu, and Mo, or a metal oxide selected from at least one metal selected from Ca, Fe, Mn, Zn, Cu, and Mo. Among these, the metal of the catalyst is preferably one of Fe, Mn and Zn, an oxide of one of these metals, or a composite oxide of two or more of these metals.

[0055] The electrolyte 38 dissolves in water to form an electrolyte solution. The electrolyte 38 is not particularly limited as long as it is a substance that allows metal ions and hydroxide ions to move between the negative electrode 31 and the negative electrode 33. The electrolyte 38 is preferably composed of, for example, magnesium acetate, sodium chloride, potassium chloride, or the like. The electrolyte solution is preferably neutral in consideration of environmental impact.

[0056] A known material can be used for the negative electrode current collector 32. When a metal is used for the negative electrode 31, the primary battery 3 may not include a negative electrode current collector, and a terminal may be taken out directly from the negative electrode 31. A known material can be used for the positive electrode current collector 34. For example, a carbon sheet, a carbon cloth, or a plate made of one or more of Fe, Cu, and Al may be used for the positive electrode current collector 34.

[0057] Here, the electrode reactions at the negative electrode 31 and the positive electrode 33 in a primary battery using magnesium metal for the negative electrode 31 will be described. When oxygen in the air and the electrolyte come into contact with the surface of the conductive positive electrode 33, the positive electrode reaction shown in formula (1) proceeds. Meanwhile, on the surface of the negative electrode 31 in contact with the electrolyte supplied by the separator 35, the negative electrode reaction shown in formula (2) proceeds. The magnesium constituting the negative electrode 31 releases electrons and dissolves in the electrolyte as magnesium ions.

[0058] The primary battery 3 can discharge due to the positive electrode reaction and the negative electrode reaction. The overall reaction is a reaction in which magnesium hydroxide is produced (precipitated) as shown in formula (3). The theoretical electromotive force is about 2.7V.

[0059] [Number 1] 1 / 2O2+H2O+2e - →2OH - ...Equation (1) Mg → Mg 2+ +2e - ...Equation (2) Mg+1 / 2O2+H2O+2e - →Mg(OH)2...Formula (3)

[0060] (How to make a primary battery) A method for producing the primary battery 3 will now be described. In the embodiment of the present invention, the primary battery 3 is produced using carbon nanofibers for the positive electrode 33.

[0061] First, a method for producing the positive electrode 33 will be described. A commercially available carbon nanofiber sol [dispersion medium: water (H2O), 0.4 wt%, manufactured by Sigma-Aldrich] was placed in a test tube, and the test tube was immersed in liquid nitrogen for 30 minutes to completely freeze the carbon nanofiber sol. After completely freezing the carbon nanofiber sol, the frozen carbon nanofiber sol was taken out into an eggplant flask, and this was dried in a vacuum of 10 Pa or less using a freeze dryer (manufactured by Tokyo Rikakikai Co., Ltd.), to obtain an elastic bicontinuum having a three-dimensional network structure containing carbon nanosheets.

[0062] Next, a method for producing the negative electrode 31 will be described. The negative electrode 31 was produced by cutting out a commercially available magnesium alloy plate AZ31B (thickness: 300 μm, manufactured by Nippon Metal) with scissors into a shape having a current collecting tab in part of a 20 mm × 20 mm square.

[0063] The separator 35 to which the electrolyte 38 is attached is produced by impregnating the separator 35 with a solution in which sodium chloride (NaCl, manufactured by Kanto Chemical) is dissolved in pure water at a concentration of 1 mol / L, and then drying at a temperature of 70°C. The separator 35 before the electrolyte 38 is attached has a square main body portion and a tape-shaped tape portion. The main body portion is a cellulose-based separator for batteries (manufactured by Nippon Kodo Paper Industries Co., Ltd.) and is formed in a square shape of 20 mm x 20 mm. The tape portion is the same cellulose-based separator as the main body portion and is formed in a tape shape of 5 mm x 50 mm.

[0064] Carbon cloth was used for the positive electrode current collector 34, and was cut into a shape of 20 mm×20 mm square having a current collecting tab on one side thereof. The positive electrode 33 was used after being cut out with a punch into a circle having a diameter of 17 mm.

[0065] A film sheet Ecologue (manufactured by Mitsubishi Plastics) was used as the material for the battery casing 37. This sheet was cut into two cut sheets measuring 30 mm×30 mm in plan view, one of which was used as the casing for the positive electrode 33 and the other was used as the casing for the negative electrode 31. An air hole 39 having a diameter of 10 mm was provided in the casing for the positive electrode 33. If the positive electrode 33 and the positive electrode current collector 34 are made of a material through which air can pass, the air hole 39 may not be provided.

[0066] The negative electrode 31, the negative electrode current collector 32, and the separator 35 are placed on the case on the negative electrode 31 side, and the positive electrode current collector 34, the positive electrode 33, and the case on the positive electrode 33 side are placed on top of this in that order, and the periphery of the two cases is heat sealed at 130° C. using a sealer to seal it. The tape portion of the separator 35 is formed so as to be exposed.

[0067] The total weight of the thus obtained primary battery 3 was about 2 g.

[0068] (Cabinet Creation) A method for producing the housing 2 will be described. As shown in FIG. 1, the housing 2 contains a primary battery 3 and a notification unit 4. The housing 2 is designed so that these fit within a size of 100 mm x 100 mm x 50 mm. The housing 2 is produced by melting and laminating PLA (Polylactic Acid) filament (manufactured by Raise3D) using the FFF (Fused Filament Fabrication) method with Raise3D Pro2 (manufactured by Raise3D). The PLA filament is made of polylactic acid. As described above, polylactic acid is a naturally decomposable material, and therefore has a small impact on the environment.

[0069] (Generation of Notification Part 4) A method for generating the notification unit 4 will be described. The LoRa / GPS tracker LT-100 (manufactured by GISUPPY) is improved so that it can be turned on, receive GPS signals, and transmit radio waves when driven by the primary battery 3. The exterior of the LoRa / GPS tracker LT-100 is removed and it is stored in the housing 2. The LoRa / GPS tracker LT-100 is connected to the positive electrode collector 34 and negative electrode collector 32 of the primary battery 3 in a non-power generating state.

[0070] Since the cell voltage is expected to be about 1.5V, power boosted to 3.7V by the power supply circuit 41 is used.

[0071] (Sensor evaluation) First, pure water is immersed in the tape portion of the separator 35 that is exposed to the outside from the case 2. The voltage change between the negative electrode 31 and the positive electrode 33 at this time is shown in FIG.

[0072] When pure water was sucked up from the separator 35, the voltage rose, and a stable voltage was obtained about 150 seconds after the start of the sucking. The voltage at this time was about 1.55V. After a stable voltage was obtained, the receiver confirmed the transmission of radio waves from the notification unit 4. The notification unit 4 also transmitted a unique ID, and the receiver confirmed the reception of this information. The receiver is a LoRa gateway ES920LRGW (manufactured by EASEL) that is capable of receiving radio waves used in the LoRa / GPS tracker LT-100.

[0073] In addition, when the sensor was placed in soil after operation, the decomposition of the casing, excluding the commercially available circuitry, was confirmed visually in about two months, indicating that it had been metabolized and decomposed by microorganisms in the soil.

[0074] In flood sensor 1 according to an embodiment of the present invention, when separator 35 that communicates with the outside becomes flooded, water is injected into separator 35 that contacts negative electrode 31 and positive electrode 33. Electrolyte 38 attached to separator 35 dissolves in water and becomes an electrolytic solution. Primary battery 3 generates electricity, and notification unit 4 is driven by the electricity generated by primary battery 3, and flooding can be notified. Primary battery 3 of flood sensor 1 does not need to operate under normal circumstances, and operates only in a situation where flooding occurs and notification unit 4 must provide a notification. Therefore, primary battery 3 does not self-discharge when not in operation, and long-term operation, for example, for more than 10 years, is possible.

[0075] By forming each component such as the housing 2 from biodegradable materials, there is no need to collect the sensor even if it is installed in the natural environment, and the burden on the environment is low. By installing the flood sensor 1 in the natural environment and having a notification server 102 installed at a location away from the flood sensor 1 receive notifications from the flood sensor 1, it becomes possible to detect disasters such as flooding that occur in faraway locations. Also, by installing multiple flood sensors 1 in the natural environment and having the notification server 102 receive notifications of flooding from these flood sensors 1, it becomes possible to grasp the scale of a disaster without visiting the site. Also, by referring to meteorological information such as the amount of rainfall at the location where the flood sensor 1 is installed, it becomes possible to determine the level of disaster alert and send an alarm to residents, etc.

[0076] (First Modification) In the embodiment of the present invention, the notification unit 4 of the flood sensor 1 has been described as including a power supply circuit 41. In contrast, the notification unit 4a of the flood sensor 1a according to the first modified example will be described as including a plurality of primary batteries 3, without including a power supply circuit, as shown in FIG.

[0077] In the flood sensor 1a according to the first modification, the notification unit 4a includes a calculation circuit 42, a communication circuit 43, and an antenna 44. A plurality of primary batteries 3 are connected in series, and power is supplied at a sufficient voltage. In such a flood sensor 1a, there is no need to boost the voltage, and the power supply circuit 41 may be omitted. In that case, the power supplied from the negative electrode current collector 32 and the positive electrode current collector 34 is provided directly to each circuit of the notification unit 4. In the example shown in FIG. 5, a primary battery 3 is connected to the calculation circuit 42 of the notification unit 4a. The communication circuit 43 and antenna 44 of the notification unit 4a are driven using power supplied from the three primary batteries 3 via the calculation circuit 42.

[0078] 5, the three primary batteries 3 are arranged horizontally, but this is not limiting. The primary batteries 3 may be connected in series and may be arranged in any manner, such as vertically.

[0079] (Second Modification) In the embodiment of the present invention, the flood sensor 1 has been described as including one primary battery 3. In contrast, the flood sensor 1b according to the second modified example will be described as including a detection sensor and a voltmeter, as shown in Fig. 6, and an arithmetic circuit 42 estimates the flood height.

[0080] The flood sensor 1b according to the second modified example includes a first detection sensor 5a, a second detection sensor 5b, a first voltmeter 6a, and a second voltmeter 6b. In the second modified example, a case in which two detection sensors are included will be described, but the flood sensor 1b may include one detection sensor, or may include three or more detection sensors.

[0081] The first detection sensor 5a and the second detection sensor 5b are provided at different heights above the primary battery 3. In the example shown in Fig. 6, the second detection sensor 5b is provided above the first detection sensor 5a.

[0082] The first detection sensor 5a has the same configuration as the primary battery 3. Specifically, the first detection sensor 5a has a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode to which an electrolyte adheres. A positive electrode current collector may be provided between the positive electrode and the separator. A negative electrode current collector may be provided between the negative electrode and the separator. When the separator of the first detection sensor 5a is submerged in water, the electrolyte attached to the separator dissolves in water to form an electrolyte solution, and the first detection sensor 5a starts generating electricity. The first voltmeter 6a measures the voltage of the power supplied by the first detection sensor 5a and inputs it to the calculation circuit 42. Since the first detection sensor 5a is provided above the primary battery 3, the first detection sensor 5a starts generating electricity when the primary battery 3 starts generating electricity and becomes further submerged.

[0083] The second detection sensor 5b and the second voltmeter 6b operate in the same manner as the first detection sensor 5a. However, since the second detection sensor 5b is provided above the first detection sensor 5a, the second detection sensor 5b starts generating power when the flooding progresses further after the first detection sensor 5a starts generating power.

[0084] When driven by power supplied from the primary battery 3, the notification unit 4 notifies that the battery is submerged at the vertical height of the primary battery 3. After being driven by power supplied from the primary battery 3, the notification unit 4 notifies that the battery is submerged at the vertical height of the first detection sensor 5a when the first detection sensor 5a detects power generation due to the submersion of the separator. The notification unit 4 recognizes power generation due to the submersion of the separator when the voltage value of the first voltmeter 6a reaches a threshold value indicating that the detection sensor 5a is generating power. After detecting power generation by the first detection sensor 5a, the notification unit 4 notifies that the battery is submerged at the vertical height of the second detection sensor 5b when the second detection sensor 5b detects power generation due to the submersion of the separator.

[0085] In the second modified example, the arithmetic circuit 42 can notify the notification server 102 of the fact that the sensor is submerged, as well as an index indicating the submergence level at the submergence sensor 1b. As shown in FIG. 6, the submergence sensor 1b includes two detection sensors in addition to the primary battery 3. The arithmetic circuit 42 specifies the submergence level at the submergence sensor 1b using three indexes. The arithmetic circuit 42 sets the specified indexes as data, and the communication circuit 43 transmits this data to the notification server 102.

[0086] After the notification unit 4 is driven by the power supplied from the primary battery 3, the voltage value of the first voltmeter 6a may be lower than the threshold value indicating the power generation of the first detection sensor 5a, and the voltage value of the second voltmeter 6b may be lower than the threshold value indicating the power generation of the second detection sensor 5b. The arithmetic circuit 42 determines that the primary battery 3, more specifically, the separator 35, is submerged in water up to the vertical height.

[0087] After the notification unit 4 is driven by the power supplied from the primary battery 3, the voltage value of the first voltmeter 6a may be higher than the threshold value indicating the power generation of the first detection sensor 5a, and the voltage value of the second voltmeter 6b may be lower than the threshold value indicating the power generation of the second detection sensor 5b. The arithmetic circuit 42 determines that the first detection sensor 5a, more specifically, the first detection sensor 5a is submerged up to the vertical height of the separator.

[0088] After it is determined that the first voltmeter 6a is higher than the threshold indicating the power generation of the first detection sensor 5a, the voltage value of the second voltmeter 6b may also be higher than the threshold indicating the power generation of the second detection sensor 5b. The calculation circuit 42 determines that the second detection sensor 5b, more specifically, the second detection sensor 5b is submerged up to the vertical height of the separator. Note that, in a state where the voltage value of the second voltmeter 6b is higher than the predetermined threshold, the value of the voltage value of the first voltmeter 6a is not important, considering the case where the first detection sensor 5a has already finished power generation.

[0089] Thus, in addition to the primary battery 3, flood sensor 1b according to the second modified example has a detection sensor having a similar configuration to the primary battery 3 installed above the primary battery 3, and further monitors the voltage generated by the detection sensor. Flood sensor 1b is able to estimate the flood height at flood sensor 1b and notify notification server 102.

[0090] The flood sensor 1b according to the second modified example can also be applied to the notification system 100 shown in Fig. 2. In that case, step S7 in the flowchart shown in Fig. 3 may determine the type of alarm depending on whether the flood height value notified from each flood sensor 1b satisfies a predetermined condition.

[0091] The notification server 102 and database server 103 of the present embodiment described above use, for example, a general-purpose computer system including a CPU (Central Processing Unit, processor) 901, a memory 902, a storage 903 (HDD: Hard Disk Drive, SSD: Solid State Drive), a communication device 904, an input device 905, and an output device 906. In this computer system, the CPU 901 executes a predetermined program loaded onto the memory 902, thereby realizing each function of the notification server 102 and the database server 103.

[0092] The notification server 102 and the database server 103 may each be implemented by one computer, or may each be implemented by multiple computers. Furthermore, the notification server 102 and the database server 103 may each be a virtual machine implemented in a computer.

[0093] The programs of the notification server 102 and the database server 103 can be stored on a computer-readable recording medium such as a HDD, SSD, USB (Universal Serial Bus) memory, CD (Compact Disc), or DVD (Digital Versatile Disc), or can be distributed via a network.

[0094] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the present invention. [Explanation of symbols]

[0095] 1. Flood sensor 2. Chassis 3 Primary battery 4 Notification section 31 Negative electrode 32 Negative electrode current collector 33 Positive electrode 34 Positive electrode current collector 35 Separator 36 Basic Cells 37 Battery case 38 Electrolytes 39 Air Hole 41 Power supply circuit 42 Arithmetic circuit 43 Communication Circuits 44 Antenna 100 Notification System 101 Base station 102 Notification Server 103 Database Server 104 Transmitting Device 901 CPU 902 Memory 903 Storage 904 Communication equipment 905 Input Device 906 Output Device

Claims

1. a notification unit that notifies the detection of flooding; A primary battery; a housing that houses the notification unit and the primary battery, The primary battery includes a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode and to which an electrolyte is attached, and an air hole for taking in air; A portion of the separator is exposed from a lower portion of the housing; When the separator is submerged in water, the electrolyte dissolves in water to form an electrolyte solution, and when the electrolyte comes into contact with oxygen in the air, the primary battery starts generating electricity, thereby supplying the power required to drive the notification unit. Flood sensor.

2. Equipped with multiple primary batteries connected in series The water submersion sensor according to claim 1 .

3. a detection sensor provided above the primary battery, The detection sensor includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode and to which an electrolyte is attached; The notification unit is notifying that the vehicle is flooded to a vertical height of the primary battery when driven by power supplied from the primary battery; After being driven by the power supplied from the primary battery, when power generation due to submersion of the separator of the detection sensor is detected, the detection sensor notifies the user that the sensor is submerged at a vertical height. The water submersion sensor according to claim 1 .

4. The negative electrode is formed of one or more metals selected from magnesium, zinc, aluminum, and iron, or an alloy containing one or more metals selected from magnesium, zinc, aluminum, and iron as a main component.

4. The water submersion sensor according to claim 1.

5. The separator is made of a water-absorbent insulating material.

5. The water submersion sensor according to claim 1.

6. A submersion sensor according to any one of claims 1 to 5, a notification server connected to the flood sensor and referencing a position and height of the flood sensor; The notification unit of the flood sensor notifies the flooding of the flood sensor, The notification server determines the importance of the alarm according to the position and height of the flood sensor that notified the flood. Notification system.

7. The notification server determines the importance of an alarm according to the number of the flood sensors that notify the occurrence of flooding. The notification system of claim 6.

8. The notification server further determines the importance of an alarm according to the amount of precipitation at the location where the flood sensor is installed. A notification system according to claim 6 or 7.

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