JP2018175730A - Nitrogen infrastructure system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide means for preventing fire/explosion accidents from being caused by hydrogen, by newly installing a nitrogen infrastructure along with the arrival of a hydrogen society in the twenty-first century.SOLUTION: In order to prevent fire/explosion accidents from being caused by hydrogen, hydrogen supply destinations are classified into three areas of an under-populated area, averagely-populated area, and over-populated area on the basis of population density considering an accident occurrence risk and, using pipe lines, a nationwide scale nitrogen infrastructure suitable for the respective areas is newly provided. Nitrogen supplied from the nitrogen infrastructure is used for not only safety measures in a hydrogen station for fuel cell vehicles but also is used for fire-prevention/extinguishment equipment in enclosed buildings such as a large-sized distribution warehouse and museum.SELECTED DRAWING: Figure 1

Description

Detailed Description of the Invention

  The present invention is to prepare for the coming of the coming hydrogen society, construct a new nitrogen infrastructure using a conduit to prevent a fire and explosion disaster caused by hydrogen, add it to the hydrogen infrastructure, and prevent the disaster caused by hydrogen in advance. Provide a means to use the built-in nitrogen infrastructure as a fireproof and extinguishing facility for large-scale enclosed buildings represented by logistics warehouses.

  Hydrogen, which is expected as the next generation clean energy, is being developed as a clean gas for preventing global warming. Above all, hydrogen for fuel cell vehicles has already been commercialized and is in the stage of practical use. On the other hand, it is said that the biggest issue for expanding demand is the maintenance of a hydrogen station for supplying hydrogen to fuel cell vehicles. The construction of the nitrogen infrastructure of the present invention is closely related to the hydrogen infrastructure for this hydrogen station.

  First, we describe the current status of hydrogen infrastructure for hydrogen stations, which is essential for the construction of nitrogen infrastructure. Hydrogen stations are divided into on-site type and off-site type depending on the location of hydrogen production site and hydrogen filling site. The on-site type refers to a station in which both are in the same place, and the off-site type refers to a method of producing hydrogen at a location remote from the filling station.

  Both have their advantages and disadvantages in terms of the location conditions of the production site and the method of transport of hydrogen, and no conclusion has been reached as to which method is superior at this time. The off-site hydrogen station has the advantage of being able to concentrate and produce a large amount of hydrogen and reduce the cost of hydrogen production, but it must be transported from the hydrogen plant to the hydrogen station.

  Methods of transporting hydrogen include a method of filling hydrogen gas into a high pressure cylinder and transporting it by a dedicated vehicle, a method of liquefying hydrogen and transporting it by a liquefied hydrogen rally vehicle, and a method of transporting it in a gaseous state using a conduit. In the present invention, a method of using a conduit is selected from these, and a new proposal is made on the premise of the existence of a hydrogen infrastructure by this conduit transportation.

  In fact, a method of supplying hydrogen to a hydrogen station using a conduit was tried in Kitakyushu City in 2011 as part of a hydrogen fuel cell demonstration project. At this hydrogen station, pure hydrogen produced from hydrogen by-produced at an adjacent steel mill was received using a conduit laid on the ground. The length of the conduit is about 2 km in total length. The project introduced this method as "the first-generation hydrogen station in Japan using a conduit".

  The first goal of this proposal is to add nitrogen into this hydrogen conduit and use nitrogen transported as a mixed gas of hydrogen and nitrogen to construct a new nitrogen infrastructure to prevent fires and explosion hazards caused by hydrogen To prevent. The background is described below.

  The use of nitrogen to avoid the danger of explosion and fire of flammable gas has long been used in the chemical industry. The reason for this is that, particularly in the case of hydrogen, the explosion range in air is wide, the ignition energy is small, the combustion speed is fast, and so on. Nitrogen is added to make the safety of hydrogen dangerous by adding nitrogen. It is for moving.

  The method of using a conduit to transport hydrogen has already been proven in Europe and the United States, and it is used for distribution among companies such as petroleum complexes in Japan. However, the method of transporting hydrogen as a mixed gas of hydrogen and nitrogen instead of using it alone is used in a part of the ammonia plant facility of a chemical plant, but the method of using it is limited, and in a wide area including urban area What has been implemented is, of course, nowhere in the world in the world.

On the other hand, attempts to improve the safety of hydrogen transport by mixing nitrogen into hydrogen have recently been reviewed and there are several new proposals. The following document is published as a method of transporting hydrogen as a mixed gas of hydrogen and nitrogen using a conduit.
JP, 2004-146312, A Unexamined-Japanese-Patent No. 2004-220802 Unexamined-Japanese-Patent No. 2006-207785 JP, 2016-193810, A

  Documents 1 and 2 describe a method of transporting hydrogen as a mixed gas of hydrogen and nitrogen instead of using hydrogen alone to avoid the explosion hazard of hydrogen. Document 3 describes a method of separating hydrogen and nitrogen from a mixed gas of hydrogen and nitrogen at a hydrogen station by a convenient method. Document 4 describes a method of detecting hydrogen leaked from a conduit in order to monitor the leakage of hydrogen gas from the conduit.

  In the case of constructing a hydrogen infrastructure by the methods shown in Patent Documents 1 to 4, it is extremely effective when implemented in a limited area. For example, in Japan, the route from Kitakyushu City to Sanyo Michido, Kinki, Tokai to Kanto is one of Japan's most overpopulated areas, and the transportation method shown in the above patent documents is suitable for that purpose.

  On the other hand, if the above method is developed in Tohoku, Hokkaido, and other regions on a global scale, for example, the United States and China, etc., which have a large land area, hydrogen plants and consumers in these areas dozens of kilometers over the wilderness It is not uncommon for cases to be separated. Even in all these areas, attempts to mix urban area nitrogen with hydrogen are excessive and not appropriate for dealing with the degree of risk.

  The same is true for the construction of nitrogen infrastructure to be added to hydrogen infrastructure. In other words, it is important to implement the most appropriate security measures for the newly constructed nitrogen infrastructure in consideration of the characteristics of the targeted area. Furthermore, the constructed nitrogen infrastructure is not limited to the safety measures of the hydrogen station, and it is necessary to add new applications that have not been made before.

  The second goal of the proposal is to use a nitrogen infrastructure built by adding hydrogen infrastructure as a new type of fire extinguishing system in a wide area using a conduit. The background is described below.

  In fire extinguishing equipment used in museums and the like, equipment for blowing in suffocating gas and extinguishing the fire has already been put to practical use in order to prevent damage to valuable works of art by water extinguishing. The gases proven as asphyxiogenic gases are halogen-based gases and nitrogen. These gases are usually filled in a special cylinder and stored in the vicinity of a building for fire extinguishing, and are released to the place where the fire occurs in case of a disaster.

When nitrogen is blown into the building to lower the oxygen concentration inside, the internal air mixes almost uniformly with the nitrogen and is dissipated to the atmosphere via the exhaust port. Academically, this mixing is called "perfect mixing".
The oxygen concentration in the interior of the building gradually decreases and reaches a concentration at which the combustible gas can not burn. The oxygen concentration at this time is called "limit oxygen concentration". This value is specific to the flammable gas and is 5.0% for hydrogen and 12.1% for methane.

  Even if the flammable matter is liquid or solid, the high temperature generates a flammable gas by evaporation of the liquid or decomposition of the solid. Therefore, to stop the combustion using nitrogen, the oxygen concentration in the building is the same as the gas. Nitrogen may be blown in until the oxygen concentration of the flammable gas is below the limit. In the case of blowing a large amount of nitrogen, it is necessary to secure an exhaust path which can exhaust the gas in the building sufficiently so that the pressure in the building will not be overpressured.

Since the amount of gas that can be stored in a normal cylinder is several m _{3 /} present, the capacity of the building to be fire fighting subject is generally limited to about several 10m ₃ ~100m _3. For this reason, the conventional fire extinguishing object was not limited to the whole building, but it had to be limited to the room for storing the most valuable works of art in the building. Thus attempts to large buildings, such as several thousand m ₃ scale warehouse as target museums entire or volume of fire extinguishing facility according to suffocating gases which such has not yet been published.

  In addition to large-scale distribution warehouses for mail order as buildings subject to the above-mentioned fire extinguishing, museums that possess valuable pictures, museums that hold combustible works, shrines and temples typified by the Golden Hall, paints etc. inside There are a wide range of buildings such as factories that handle flammable materials, and closed buildings that may generate flammable gas in the event of an accident.

  These objects are based on water fire extinguishing combined with a smoke detector and a sprinkler in the conventional fire extinguishing method, and it is difficult to cope with covering the entire building area, and a new fire extinguishing system has been desired. The present invention provides an effective and inventive means to renew the existing solution to this problem.

  On the other hand, when using the present invention on a national scale, an important issue that needs to be particularly noted is the prevention of human accidents or accidents associated with oxygen deficiency.

  The present invention has been made in view of the above problems, and utilizes a newly constructed nitrogen infrastructure added to a hydrogen infrastructure for a hydrogen station to prevent the occurrence of fires and explosions caused by hydrogen and also to increase the size It provides a means to utilize as fire extinguishing equipment of a sealed building represented by a distribution warehouse.

  The first solution to the construction of the nitrogen infrastructure is to provide a means by which the construction of the new nitrogen infrastructure can be implemented at the same time as the construction of the hydrogen infrastructure to be constructed separately from this infrastructure. As already described in detail, the idea of building a nitrogen infrastructure has never been considered, and the related information has not been disclosed. The biggest reason is that in the case of nitrogen alone, there was no demand for utilizing nitrogen.

  However, hydrogen has attracted attention as a clean energy for preventing global warming until the end of this century, and construction of a hydrogen station for fuel cell vehicles has started. In addition, there has been a large-scale fire accident at a large-scale distribution warehouse or an unmanned paint factory for automobiles due to the rapid increase in internet sales, and the fire extinguishing system has been reviewed. For these new needs, the help of nitrogen is absolutely necessary for disaster prevention. The second solution to this solution is to find a way to supply nitrogen along with hydrogen to national customers.

  The third solution is to supply the supplied nitrogen and hydrogen in the most efficient manner according to the environment of the customer. Most consumers of hydrogen and nitrogen are from their manufacturers. For example, in large cities such as Tokyo, where demand is for major cities, regional core cities, and cold villages, the risk of occurrence of an accident differs greatly. Therefore, the supply method is not uniform, and it is necessary to provide a unique method suitable for the area. Furthermore, it is important to select the method that combines the above methods most efficiently in order to expand this nitrogen infrastructure nationwide.

  A major feature of the present invention is that the composition ratio of hydrogen and nitrogen can be arbitrarily adjusted in order to provide this unique system. For this purpose, a technique for accurately detecting the mixed gas component of hydrogen and nitrogen and an apparatus capable of arbitrarily adjusting the composition ratio are required. In this proposal, the most suitable equipment is selected and designated from among models that have already been proven for these equipment.

  Next, the fourth solution for establishing the nitrogen infrastructure is to find new and unprecedented applications for further expansion of demanders. In the present invention, the application to the fire extinguishing equipment of a closed building represented by a large-sized distribution warehouse is presented as its application.

  To blow nitrogen into the building and use it for fire prevention is to replace the oxygen, which is the combustion supporting gas in the building, with nitrogen so that combustion can not be continued. The following is a basic matter of replacing nitrogen by nitrogen with the nitrogen supporting gas (= oxygen) in a building.

上式より空気中の酸素を限界酸素濃度ａ_２まで低下させる窒素量 Ｖは

例えば建屋容積＝７，０００ｍ３、目標の酸素濃度（＝水素の限界酸素濃度）＝５％を

即ち容積７，０００ｍ３の建屋内の酸素を窒素で置換して燃焼を継続できない酸素濃度まで低減させるには可燃性ガスを水素と仮定した場合、容量で約１０，０００ｍ３の窒素が必要である。A volume (Vm ₃ ) of nitrogen is blown into the interior of a building having a volume (Am ₃ ) to release the same amount of gas in the building, and the oxygen concentration in the building is targeted from the normal concentration (a ₁ = 21%). In the case of reduction to the oxygen concentration (a ₂ %), the reduction curve is represented by the following function according to the “perfect mixing formula”. Here, e is a constant called the number of napiers.

From the above equation, the nitrogen content to reduce oxygen in air to the limit oxygen concentration a ₂

For example, building volume = 7,000 m3, target oxygen concentration (= limit oxygen concentration of hydrogen = 5%)

That is, in order to replace oxygen in a building with a volume of 7,000 m 3 with nitrogen to reduce the concentration of oxygen to which combustion can not be continued, assuming that the flammable gas is hydrogen, about 10,000 m 3 of nitrogen in volume is required.

  The fifth solution is to establish measures to prevent oxygen deficiency, which is also called the negative effect associated with the use of nitrogen. When the concentration of oxygen in the atmosphere drops to about 10%, human beings lose consciousness, and at 6% or less, there is a danger of death in a few minutes. Although these cases are predominantly caused by human errors, there is a rare risk of being caused by artificial acts or malicious acts.

  Nitrogen is effective for preventing fires and fires by lowering the concentration of combustion supporting gas, but it may cause oxygen deficiency due to lack of oxygen. This preventive measure should be considered in advance and always implemented. Without such protective measures, it is difficult to stably spread the nitrogen infrastructure. The details of the protective means will be described in the following "Best Mode for Implementation".

  Judging from the probability of fires and explosions, hydrogen is an extremely dangerous substance compared to gasoline and kerosene. If safety can be backed up to a hydrogen infrastructure utilizing a nitrogen infrastructure by the present invention, it will greatly contribute to disaster prevention in order to realize a hydrogen society expected as next-generation energy.

  Furthermore, the nitrogen infrastructure built in a wide area can be used as a fire prevention equipment for large buildings etc. in a simple way, and its applications will be expanded. On the other hand, it is necessary to give due consideration to the prevention of the occurrence of an oxygen deficiency accident that is of new concern with the introduction of nitrogen.

  As described in detail above, the present invention is constructed in conjunction with a conduit-based hydrogen infrastructure, so the hydrogen infrastructure is first shown in FIG. Although hydrogen produced at a hydrogen production plant is usually sent to a hydrogen station, which is a hydrogen supply destination, using a conduit, in the present invention, the hydrogen supply destination is classified as A, B, or C according to the risk of fire or explosion. Divide into areas.

  Although this risk of occurrence usually depends on the population density, the classification can also be changed according to the surrounding environment. The classification of the above areas is not strict. If new infrastructure is to be built in the future, it will be decided according to the regulations led by the supervisory authority that oversees the area, where C is overpopulated area, B is overpopulated area and A is average population area.

  For example, when hydrogen produced at a factory in Muroran, Hokkaido is transported to Sapporo using a conduit, Muroran City is Area A, Sapporo City is Area C, and the rural area connecting the two cities is Area B. When transporting combustible gases such as hydrogen using conventional conduits, such division of the area was not performed, and the same measures were taken throughout the whole area. However, in the present invention, the supply destinations are classified to select the most suitable transportation method in the area.

  Next, only the nitrogen infrastructure part of the present invention is taken out and shown in FIG. The nitrogen infrastructure shown in FIG. 3 supplies the supply destinations to the A, B, and C regions, as in the hydrogen infrastructure of FIG. 2, but the configuration of the device differs depending on each region. The main equipment and equipment configured in FIG. 3 are a nitrogen plant, a nitrogen conduit, a hydrogen / nitrogen mixer, a hydrogen / nitrogen separator and a hydrogen purifier.

  Area A consists of a nitrogen plant, a nitrogen conduit, a hydrogen / nitrogen mixer and a hydrogen purifier. A nitrogen plant in this area will be located near the hydrogen plant to mix the nitrogen from the hydrogen plant as soon as possible. For example, when using hydrogen from COG gas generated at a steelmaking plant, nitrogen by-produced together with oxygen used for oxygen steelmaking at the same steelmaking plant is utilized as a nitrogen production plant.

  Area B consists of hydrogen and nitrogen separators, hydrogen pipes and hydrogen purifiers, and area C consists of nitrogen plants, hydrogen and nitrogen mixers, nitrogen pipes, hydrogen purifiers and nitrogen recycle pipes. The configuration when this nitrogen infrastructure is added to the above-mentioned hydrogen infrastructure is shown in FIG. FIG. 1 is a combination of the concepts shown in FIGS. 2 and 3, and is a representative view showing the configuration of the present invention.

  It is in area A that the mixed gas of hydrogen and nitrogen is sent first. For example, this hydrogen / nitrogen mixed gas is adjusted to the H2 / N2 = 70/30 (volume ratio) mixing ratio of the two gases and sent to a hydrogen station existing in the same area. In the hydrogen station, nitrogen is completely separated by a hydrogen purifier and hydrogen is charged into a fuel cell vehicle. The separated nitrogen is released to the atmosphere through a nitrogen vent pipe.

  The mixed gas of hydrogen and nitrogen is then sent to area B. Area B is a sparsely-populated area connecting the hydrogen production plant and area C, which is the main supply destination of hydrogen, and is the area with the lowest probability of occurrence from the viewpoint of the risk of fire and explosion. Here, a hydrogen / nitrogen separator is first used to remove most of nitrogen in the mixed gas, and the hydrogen / nitrogen mixture ratio is adjusted to, for example, H2 / N2 = 90/10 (volume ratio).

  With this composition, it is sent to a hydrogen station scattered in the same area, and in the hydrogen station, nitrogen is completely separated by a hydrogen purifier, and the fuel cell vehicle is charged with hydrogen. Nitrogen separated in this area is released to the atmosphere through a nitrogen vent pipe. The reason for separating most of the nitrogen in the B area is to reduce the cost of pipeline installation and reduce the cost of transportation.

  The mixed gas of hydrogen and nitrogen is then sent to area C. Area C is the largest consumption area of hydrogen and has the highest population density and a high probability of fires and explosions. Here, first, nitrogen is mixed with mixed gas from a nitrogen plant using a hydrogen / nitrogen mixer, and the mixing ratio of hydrogen / nitrogen is adjusted to, for example, H2 / N2 = 50/50 (volume ratio), and is present in the same area Sent to the hydrogen station. At the hydrogen station, after hydrogen is completely separated using a hydrogen purifier, hydrogen is charged into a fuel cell vehicle.

  Unlike the other areas, nitrogen separated in area C is recycled to the nitrogen plant through piping. Normally, separate pipes are provided and transported for this nitrogen recycle, but a double pipe is used for all or part of the nitrogen recycle pipes, and a mixed gas of hydrogen and nitrogen is used for the inner pipe side for the outer pipe side. Alternatively, nitrogen may be flowed. In addition to the facilities for receiving recycled nitrogen from the hydrogen station described above, facilities for receiving liquefied nitrogen, which will be described later, are also installed at the nitrogen production site installed in Area C.

  The above is the basic configuration to "utilize the nitrogen infrastructure to prevent the occurrence of fires and explosions of the hydrogen infrastructure" which is the first object of the present invention. The actual nitrogen infrastructure is constructed by combining these with various regions. An example is shown in FIG. The combination of these is based on the configuration shown in FIG. 1, but the combination may be arbitrary when developed in a wide area. For example, as shown in FIG. 4, the area A may be directly supplied to the area C, or the area C may be further divided and supplied in parallel or in series.

  When the present invention is performed throughout Japan, for example, free combinations as shown in FIG. 4 under the hydrogen infrastructure and nitrogen infrastructure shown in the present invention by several tens of off-site hydrogen production stations and several thousands of hydrogen stations. Tied with As a result, it is possible to construct hydrogen and nitrogen infrastructure simultaneously and simultaneously in a safer and less laborious way compared to previously proposed measures.

  Furthermore, the development of hydrogen infrastructure in the past has been limited to a limited area, as shown in the example of Kitakyushu City described above. The construction of hydrogen and nitrogen infrastructures for the prevention of global warming must be a concept that can be developed at least throughout Japan, as well as in countries with large land areas such as China and the United States. The invention leaves this possibility for global deployment.

  Next, supplementation is performed on separation, mixing, and purification of hydrogen and nitrogen used in the present invention. A major feature of the present invention is that in the constructed hydrogen and nitrogen infrastructure, the mixing ratio of hydrogen and nitrogen can be adjusted arbitrarily and accurately. For this purpose, first of all, a technology for accurately measuring the mixing ratio of the two is essential.

  What is selected as the first candidate as a method of accurately measuring the hydrogen gas concentration in nitrogen gas is a method of utilizing thermal conductivity. This measurement method makes use of the fact that the thermal conductivity of hydrogen is an order of magnitude smaller than that of nitrogen. Fortunately, hydrogen and nitrogen targeted by the present invention are for fuel cell vehicles, and are extremely suitable for this measurement method because they are extremely low in impurities other than hydrogen and nitrogen and extremely high in purity.

The second candidate is a method using electrical conductivity. For example, a measuring method using a thin film of Pt / WO ₃ or SnO ₂ is sufficiently applicable as a new measurement of hydrogen concentration. This method is characterized in that it is compact and easy to automate in common with the method of the preceding paragraph. Furthermore, it has the advantage of safety because it does not have a heating part in the measurement part.

  The next issue is what type of measurement results shown above are used to separate and purify hydrogen and nitrogen. The first model is a model using a membrane separation system that utilizes the size difference between hydrogen and nitrogen molecules. Next, there is a model that utilizes the difference in adsorption power to a solid adsorptive material as represented by molecular sieve. Gas separation and purification methods utilizing these models have already been put to practical use, and can be applied to the present invention sufficiently.

  In the present invention, these devices are used for a hydrogen / nitrogen mixer, a hydrogen / nitrogen separator and a hydrogen purifier. The internal hydrogen purifier is usually installed in a hydrogen station, and in many cases subject to restrictions on the area of the site, a membrane separation system that is easy to miniaturize is suitable.

  On the other hand, hydrogen and nitrogen separators and hydrogen and nitrogen mixers are usually installed in the main line of hydrogen and nitrogen mixed gas, so there is less concern about site constraints. Furthermore, in addition to the measurement of the gas concentration, these models also need to perform proportional control combining the above measurement result of the concentration and the flow meter in order to perform accurate separation and mixing operation. It is displayed, but rather close to the device. In this case, an appropriate combination is selected from the models described above in accordance with the environment of the installation location.

  Next, the second goal of the present invention, "utilizing nitrogen infrastructure for fire prevention measures for buildings," will be described. It has already been described that nitrogen reduces the concentration of the support gas (= oxygen) to stop the combustion among the three components of combustion, "flammable materials", "support gas" and "ignition source". Here, a specific method of using the nitrogen infrastructure of the present invention for fireproofing measures for buildings is described.

  A schematic diagram of using nitrogen infrastructure as fireproof and fire extinguishing equipment for buildings is shown in [Figure 5]. In this figure, a route for supplying nitrogen to a target building from a nitrogen supply facility using piping is shown in accordance with the previous regional division. The building that is the object of fire prevention and extinguishing is a closed building represented by a large-scale distribution warehouse as already described in the technical background of the text.

  According to the regional division, the nitrogen supply facility in the A region includes a nitrogen production site in or near a hydrogen production site. Currently, promising candidates for hydrogen production include chemical plants, petrochemical complex companies, and steel plants, all of which secure sufficient nitrogen for self-consumption and security use, and are concerned about supply There is no. From these nitrogen supply facilities, nitrogen is supplied to the target building at a medium pressure of 1 MPa or less at a supply pressure using dedicated piping.

  The nitrogen supply facility in Area B utilizes nitrogen released from the hydrogen and nitrogen separator installed in the mixed gas line of hydrogen and nitrogen. This nitrogen is usually released to the atmosphere. Generally, the number of buildings existing in this area is smaller than in other areas, but in the event of an emergency, this radiation is canceled and nitrogen is supplied to the target building using dedicated piping.

  Furthermore, if there is an isolated target building in area B, and it is difficult to transport nitrogen by piping because it is a long distance from the hydrogen / nitrogen separator, a backup method by liquefied nitrogen rally car described later is adopted as a special case. For example, there is a military base in area B where it is possible to blow in liquid nitrogen directly into the storage space, and in this case there is a case where the storage for storing dangerous materials such as explosives on the site is exposed to fire or explosion hazard. Applicable

  Area C is an area where the number of buildings targeted is overwhelmingly greater than in other areas. Nitrogen supply facilities in this area include nitrogen plants in the area. In addition to producing nitrogen itself, the nitrogen plant recycles nitrogen using piping from a local hydrogen station. Furthermore, because there are many buildings to be targeted, it is important to establish a nitrogen backup system so that the supply of nitrogen will not be interrupted in the event of an emergency.

  As a backup of this, Fig. 5 shows the supply by the liquefied nitrogen troll car. At present, in urban areas, the distribution of liquefied oxygen by a dedicated lorry has already been established for oxygen inhalation in hospitals. Liquefied oxygen is produced by an air / cryogenic separator located in the same area, where liquefied nitrogen is co-produced. This liquefied nitrogen is transported to a nitrogen supply facility using a dedicated rori vehicle and used as backup nitrogen.

  Next, the method of using nitrogen supplied using dedicated piping as a fire extinguishing system in the target building will be described. In order to enhance the suffocating effect of nitrogen, it is important to introduce the air staying inside while keeping the airtightness of the building as much as possible to the exhaust system together with the blown nitrogen. First, in order to make effective use of the effects of the present invention, the structure of a target building body will be described.

  The building to which the present invention is applied is a large-scale building represented by a distribution warehouse, and usually has several floors and a closed type structure with few openings except for the entrance. Although the top floor of the building has a ventilating section leading to the atmosphere, it does not have a structure capable of exhausting a large amount of nitrogen that can be blown in an emergency.

  In a building having such a structure, in addition to a normal ventilation unit, it is necessary to separately secure an exhaust path that can be used temporarily in preparation for the blowing of a large amount of nitrogen in an emergency. Specifically, a ventilation gate or a rupture disk (= rupture disc) may be provided in this path to normally shut off from the atmosphere, and these devices may be opened only in the event of an emergency. By this measure, a large amount of nitrogen introduced from above the ground is sufficiently mixed with the air in the building to be released from the roof to the atmosphere via the exhaust path without pressurizing the building.

  Next, we will describe how to connect the nitrogen piping branched from the nitrogen infrastructure with the fire prevention equipment of the building at the target building site. [FIG. 6] shows a schematic view of the connection part. Both pipes are not connected normally as shown in FIG. 6, but are connected using a dedicated connection pipe only in case of emergency. This is because, if there is a human being in the building, there is a risk that a serious disaster may occur due to oxygen deficiency if nitrogen is mistakenly introduced.

  In order to prevent this risk, the upper part of Fig. 6 is connected to the nitrogen piping using the connection piping in an emergency, and the nitrogen source is used unless a specific password owned by a previously designated administrator is input to the password input device. Protective measures are shown that can not release the valve lock function. In the lower part of Fig. 6, in addition to this protective measure, "fire occurrence information by smoke detection", "unmanned confirmation information by infrared sensor" and "ventilation confirmation information such as opening of ventilation gate" are incorporated. Safety measures are being added in order to add protection measures that can not be released.

  In the spread of nitrogen infrastructure, in addition to the above-mentioned measures on the hardware side, it is necessary to establish measures to prevent accidents and disasters due to oxygen deficiency also on the software side. As specific measures, it is considered that all the buildings to be targeted are authorized and authorized by the competent government authorities, and that the buildings are obliged to require the retention of a manager for preventing the lack of oxygen. The nitrogen infrastructure introduced to ensure safety must not be a weapon to kill lives.

  If a nitrogen infrastructure using a conduit can be established according to the present invention, it will not only contribute to the safety measures of hydrogen stations for fuel cell vehicles on a national scale, but also if a large enclosed building encounters a fire risk new type of unprecedented It can be used as fire extinguishing equipment.

It is the schematic which shows the structure of the hydrogen infrastructure and nitrogen infrastructure which used the conduit | pipe. It is a schematic diagram showing composition of hydrogen infrastructure using a conduit. It is the schematic which shows the structure of the nitrogen infrastructure which used the conduit | pipe. It is the schematic which shows the structure which combined hydrogen infrastructure and nitrogen infrastructure. It is a schematic view showing fire prevention and backup to a building of nitrogen infrastructure. It is the schematic which shows the fire suppression equipment by nitrogen.

1 hydrogen plant 2 nitrogen plant 3 hydrogen and nitrogen mixer 4 hydrogen and nitrogen separator 5 hydrogen purifier 6 hydrogen station 7 fuel cell vehicle 8 hydrogen and nitrogen mixed gas pipe 9 nitrogen pipe 9 nitrogen vent pipe 10 nitrogen pipe 11 nitrogen Recycle piping 12 Target building 13 Air separator 14 Hospital 15 Liquefied oxygen rally transportation 16 Liquefied nitrogen rally transportation 17 Nitrogen main valve lock function 18 (Nitrogen main valve opening and closing) password input device 19 Connection piping 20 Hydrogen conduit A A population average area B population Depopulated area C Population dense area D Target building site

Furthermore, if there is an isolated target building in area B and it is difficult to transport nitrogen by piping because it is a long distance from the hydrogen / nitrogen separator, a backup method using a liquefied nitrogen rally car described later is adopted as a special case. It is also possible to blow liquefied nitrogen directly into the For example there is the base of the SDF in B area, the case where warehouses store exposed to the risk of fire, explosion explosives such hazardous materials in its site corresponds to this.

Claims (6)

  A nitrogen supply facility of a nitrogen plant used in a wide area where a hydrogen infrastructure using a conduit exists, and nitrogen is mixed into the hydrogen conduit from the nitrogen plant using a conduit to form a mixed gas of hydrogen and nitrogen. Furthermore, according to the population density of the supply destination, the supply area is classified into three areas of depopulated area, densely populated area and population average area, and nitrogen production site, nitrogen conduit, hydrogen / nitrogen mixer, hydrogen / nitrogen separator, hydrogen purification A nitrogen infrastructure system characterized in that the supply system of an independent configuration is defined for each area by using a vessel, and nitrogen is supplied to each area as a hydrogen / nitrogen mixed gas or a nitrogen single gas.   The nitrogen supply facility of the nitrogen plant is equipped with either a nitrogen production facility or a nitrogen recycling facility, or both, and using a hydrogen / nitrogen mixer and a hydrogen / nitrogen separator, the mixing ratio of hydrogen and nitrogen in the gas is Arbitrary composition adjusted to mixed gas of hydrogen and nitrogen or single gas of nitrogen, the area is classified according to the above regional division, and nitrogen is mixed with hydrogen and nitrogen mixed gas or nitrogen using a conduit to the combined destination The nitrogen infrastructure system according to claim 1, wherein the nitrogen infrastructure system is supplied as a single gas. The hydrogen and nitrogen mixers and hydrogen and nitrogen separators of the nitrogen infrastructure use the difference in the size of hydrogen molecules and nitrogen molecules, or the difference in adsorption power of hydrogen molecules and nitrogen molecules on solid adsorptive substances. In the adsorption method, when measuring the concentration of hydrogen and nitrogen in the mixed gas of hydrogen and nitrogen, the concentration of hydrogen and nitrogen in the hydrogen / nitrogen mixed gas using the difference in thermal conductivity or electric conductivity of both gases The nitrogen infrastructure system according to claim 1, wherein the mixing ratio of hydrogen and nitrogen can be arbitrarily adjusted.   In addition to the fact that the nitrogen infrastructure is used as a disaster prevention facility for hydrogen infrastructure, a new type of nitrogen supply facility for nitrogen infrastructure is used to newly branch piping of nitrogen from the nitrogen supply facility to form an enclosed type such as a distribution warehouse or museum in the above three areas. At the time of occurrence or anticipation of occurrence of a disaster in a building, nitrogen gas is blown into the building to lower the oxygen concentration in the building to be utilized as a fire extinguishing facility to prevent fire and explosion disaster of the building. Nitrogen infrastructure system described in.   When the closed type building of the nitrogen infrastructure supplies nitrogen from the nitrogen supply facility to the target building at the site of the same building, the fire prevention and extinguishing facility of the building via the nitrogen main valve lock function operated by dedicated connection piping and opening and closing signals. The nitrogen infrastructure system according to claim 1, wherein the nitrogen infrastructure system is connected to   The nitrogen supply facility of the nitrogen infrastructure uses the nitrogen separated from the air separation device in the area where the facility is present as liquefied nitrogen, and transports it to the nitrogen supply facility and the fire prevention equipment of the building using a liquefied nitrogen rally car The nitrogen infrastructure system according to claim 1, wherein the nitrogen infrastructure system is used as a backup for nitrogen supply.

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