RU2677712C2 - Method of increasing fire safety inside of hermetic objects, mainly underwater boats - Google Patents

Abstract

FIELD: fire safety.SUBSTANCE: after sealing in the inhabited object, a gas-air medium is created at such an elevated pressure at which the volume concentration of oxygen is set at about 14 vol %, which reduces the probability of fire and fire due to a reduction in the oxygen content in it, and the oxygen partial pressure is about 19.2 kPa, which ensures the preservation of the conditions for the normal life of the crew due to the maintenance of partial pressure at the no-hypoxic level, and when receiving a signal from the means pre-alarm PFI is performed further regulate the oxygen content by reducing the pressure to an acceptable level or remove a portion of the oxygen from the hot water to reduce the oxygen percentage, while maintaining the hot water pressure. The regulation is made during the search for the source of danger, after which the initial hot water pressure parameters are restored. An assessment of the probability of occurrence and development of a fire under the conditions of the proposed hot water supply provides a significant reduction in the probability of a fire. The method is implemented using a known device.EFFECT: increased fire safety of submarines and other sealed inhabited objects by creating them hypoxic gas medium with a high content of argon, reduces the likelihood of ignition and fire due to the reduced content of oxygen while creating the conditions for the normal life of the submarine crew in a long hike.2 cl, 3 dwg

Description

The invention relates to the field of fire safety of submarines and other hermetically sealed inhabited objects, including protected command posts, aircraft cabins, industrial laboratory and storage facilities, etc. that can withstand increased air pressure inside the object.

Improving the fire safety of submarines (hereinafter - PL) and other sealed inhabited objects is an urgent scientific and technical task, the solution of which can reduce the risk of death of people and equipment.

In recent years, the possibility of creating gas-air media on submarines that reduce the likelihood of fire and fire due to a decrease in the oxygen content in them has been widely studied.

Known methods and devices for increasing the fire safety of rooms and storages of fire-hazardous objects by creating gas-air media in them with a low oxygen content up to 8% of the volume (hereinafter - vol.%) By diluting them with an inert gas. Currently, they have been used to ensure the fire safety of museum storages, library storages, warehouses of especially fire hazardous technical media and facilities, granaries, etc. (see, for example, the article “Gas fire extinguishing” at the Internet link http: // os -info.ru/pojarotuschenie/gazovoe-pozharotushenie.html, as well as GOST 12.1.010-76. Explosion protection. General requirements; Ensuring fire safety of silos and bins at grain storage and processing enterprises, http: //www.ktm-star .com / katalog / pogarnaya-bezopasnost.html).

The devices described in these sources are either nitrogen cylinders, an environmental control system and flow control, or nitrogen generators, as in the article “Nitrogen Extinguishing Systems” (see the Internet link http://www.grasys.ru/products/ gas / fire /), which extract it from the ambient air and then supply the required amount to the room to maintain a certain composition of the medium.

However, it is obvious that such fire safety enhancements are applicable only to sealed rooms and storage facilities, which, at the same time, have the technical ability to connect their volumes with atmospheric air, for example, to enrich a hot water tank with oxygen or nitrogen from the outside atmosphere or, conversely, to bleed them in atmosphere. In addition, during the storage of fire hazardous facilities in secure premises, the presence of people for whom the above oxygen content may be fatal is not expected, i.e. such methods are not intended, for example, for use in aircraft, space objects, or submarines.

Also known is a hypoxic fire suppression and fire prevention system according to Norwegian patent No. NO20024955 (A), IPC A62C 2/00; A62C 3/00; A62C 99/00; A62D 1/00; A62D 1/02; B01D 53/02, publ. December 5, 2002, according to which it is proposed to use fire prevention and elimination systems for all inhabited objects and submarines at standard atmospheric pressure, in which a fire-extinguishing composition of a mixture of nitrogen and oxygen with an oxygen content of 12 to 17 vol. % with the possible addition of carbon dioxide. When implementing this method for sealed submarines when applying a mixture of nitrogen and oxygen with a percentage of oxygen from 12 vol. % in the submarine there will be a decrease in oxygen concentration to values that impede combustion, with a simultaneous increase in pressure above the permissible value for ship equipment. So, to achieve an oxygen concentration in the air of 14 vol. %, at which self-sustaining combustion of most of the main ship materials, which are potential sources of ignition and fire spreading on the submarine, is impossible, it will be necessary to increase the pressure in the sealed room 2.3 times to 232 kPa. The crew after working in these conditions during autonomous navigation will require a long decompression. In addition, the proposed method does not establish acceptable time limits for the stay of the crew in the created conditions without damage to health.

There is also known a way to increase the fire safety of submarines by monitoring the pre-fire conditions of the air, technical means and equipment - sources of fire danger (the method of pre-emergency, emergency and post-emergency control of sources of radiation, chemical and fire hazard in sealed habitable objects, mainly submarines, and an integrated system for its implementation: Pat. No. 2596063 Russian Federation / Petrov V.A., Abakumov V.P., Zhabrunov V.I. [et al.]; Applicant and patent holder About "ASM» - №2015127771 / 12 (043121). Appl 10.07 2015)...

Pre-emergency control (PAC) is carried out in order to prevent the uncontrolled transition of sources of explosive and other types of danger to the pre-emergency state and to ensure the possibility of timely regulation when the sources of fire danger enter the pre-emergency state by identifying it and informing the decision maker about the event.

A known method of preventing fires inside sealed habitable objects, mainly submarines, and a device for its implementation, (Pat. 2549055 Russian Federation, IPC A62C 3/00, A62C 2/00 / Petrov V.A., Budarin S.N., Mikhailenko BC [et al.]; Applicant and patent holder of ASM JSC. - No. 2014108499; filed March 6, 2014.)

According to the claims, the method consists in the fact that inside each enclosed space of a sealed object, a hypoxic gas-air medium is formed with a set initial low oxygen content at normal DHW pressure, and the oxygen content is set depending on the type of sealed room, due to the residence time and the intensity of the crew him, simultaneously monitor and identify the status of fire hazard sources by measuring in continuous mode or at predetermined time intervals of at least one characteristic parameter of the pre-emergency pre-fire condition of the controlled gas-air medium, technical means and equipment, in the event of a signal about the achievement or excess of the set values of at least one characteristic parameter of the pre-emergency pre-fire state of the controlled gas-air medium, technical means and equipment regulate oxygen content and hypoxic gas pressure air environment in an airtight room by lowering the oxygen content and increasing the nitrogen or inert gas content to the concentrations and pressures prescribed for this room and preventing or reducing the likelihood of fire of technical equipment and equipment for a specified period of time during which stay inside the airtight room safe for the crew and equipment, and after conducting measures to find the causes and source of the pre-emergency pre-emergency signal The aromatic state and its elimination restore the initial preset value of the oxygen content at normal dhw pressure for each enclosed space of an airtight object.

This method is effective, but for rooms with a permanent round-the-clock stay, it assumes an initial oxygen content of 19% vol., Which in the case of a rapid development of a pre-emergency fire hazard situation can cause a delay in preventing fire and fire by regulating with a decrease in oxygen concentration.

There is a method of creating conditions for human life in a pressure chamber according to the patent of the Russian Federation No. 2138421, IPC B63C 11/00, B63C 11/36, publ. 09/27/1999 (inactive), adopted as a prototype. According to the method, to increase the fire safety of the submarine, it is proposed to use an oxygen-nitrogen medium with an oxygen content of 14 ± 1 vol. % and maintaining high air pressure for the entire time of sealing so that the partial oxygen pressure in the medium corresponded to normoxic and amounted to 20-21 kPa, which is necessary to prevent the hypoxic state of crew members. The air pressure of the submarine will correspond to 150 kPa, that is, almost 1.5 times higher than normal atmospheric pressure.

Such an environment significantly increases fire safety, but does not impede the possibility of ignition and decay of some substances during heat supply. Elevated pressure also affects the crew and equipment of the facility and it is desirable, if possible, to reduce it.

There is a method (report on OCD "Argon") in which in a normobaric hypoxic gas-air environment create an increased concentration of argon up to 35 vol. %, and the oxygen concentration is set at a level of 12 to 14 vol. % for premises of permanent round-the-clock stay and regulate the oxygen content in it when receiving a signal from the means of pre-emergency pre-fire monitoring with a decrease in concentration for the required time, up to 8 vol. %, which ensures the impossibility of ignition and decay (at such an oxygen concentration it is impossible to burn methane, gasoline, etc. [D. Dreisel, Introduction to the dynamics of fires, M., Stroyizdat, 1990]).

This method is safe for the crew, but difficult to implement on large sealed facilities, such as submarines, due to the need to have a large supply of argon on board, and also because it is currently difficult to separate argon from air in autonomous conditions on the technical side.

The claimed invention solves the following tasks:

- prevent fire or fire on submarines and other inhabited airtight objects during their long autonomous operation;

- to ensure long-term work of the crew for 1-100 or more days without significant reduction in performance and damage to health;

- to ensure the preservation of the main modes of operation of the facility and the preservation of the operability of the facility's equipment.

The technical result from the implementation of the claimed invention is to increase the fire safety of the object during sealing by creating a gas-air medium in it with such an increased pressure at which the volume concentration of oxygen is set at about 14% vol., Providing a decrease in the probability of fire and fire due to a decrease in the oxygen content in it , and the partial pressure of oxygen is about 19.2 kPa, which ensures the preservation of conditions for the normal functioning of the crew following maintaining partial pressure at a non-toxic level and regulating the oxygen content upon receipt of a signal from pre-emergency pre-fire monitoring equipment (RF patent No. 2596063, IPC G21C 17/00, published on 08.27.2016) by reducing the pressure to an acceptable level or removing part of the oxygen from the hot water supply, to reduce the percentage of oxygen, while maintaining the hot water pressure, while searching for the source of danger, with the subsequent restoration of the initial parameters of hot water. Assessment of the probability of occurrence and development of a fire in the conditions of the proposed hot water supply gives a significant amount of reduction in the probability of a fire.

To achieve this technical result, in the claimed method of preventing fires at the facility, the following is implemented:

- at the facility as a whole, domestic hot water is formed with an oxygen content of about 14% vol, while maintaining such an increased pressure of the air medium for the entire time of sealing, at which the partial pressure of oxygen in the gas-air medium meets the normative pressure and is about 19.2 kPa, which complies with regulatory requirements (19 vol.% when NU) and ensures the prevention of the hypoxic state of crew members. The air pressure of the submarine will correspond to about 140 kPa, that is, almost 1.4 times higher than normal atmospheric pressure;

- the DHW pressure is regulated, with its decrease to 101-120 kPa for a specified time, after receiving a signal about the pre-emergency pre-fire condition of the fire hazard source, which, while maintaining the oxygen percentage at about 14%, reduces the absolute oxygen content with a decrease in its partial pressure up to 13.8-16.8 kPa, leading to moderate hypoxia, but providing a reduction in fire hazard during the search for a source of danger (30-60 minutes) by reducing the likelihood of a reaction due to a decrease in a lucid number of oxidant molecules and a decrease in the diffusion rate of the oxidizing agent to the fire hazard source;

- either - they adjust the oxygen content in the hot water supply during the search for a source of danger with a decrease in its concentration by separating air into oxygen and nitrogen through an air separation unit while maintaining the hot water pressure, which also reduces the fire hazard by reducing the partial pressure and oxygen concentration. At the same time, it is permissible to reduce the oxygen concentration for a time, as a rule, up to 4 hours without consequences for the working capacity and health of crew members (Ivanov A.O., Belyaev V.F., Petrov V.A., Bezkishky E.N., Tagirov R .T. Investigation of the possibility of periodic stay of a person in artificial normobaric gas environments that reduce the risk of fires in submarines // Transactions of VMPI VUNTS Navy VMA. - 2016. - No. 2 (18). - P.208-212), which is recounted under normal conditions involves a decrease in oxygen concentration to a level of 17 vol. % (17.2 kPa) of the corresponding 12 vol. % oxygen at a dhw pressure of 140 kPa;

- either combine both of the above methods;

- after identifying the source of the fire hazard in the pre-emergency pre-fire condition and normalizing its state or shutting down, the initial parameters of the hot water supply are restored at the hot water pressure level of about 140 kPa and the partial oxygen pressure of about 19.2 kPa.

In this case, the restoration of the initial set values of the oxygen content and pressure of the air-gas medium is carried out without using outside atmospheric air, in particular, without floating the submarine above the surface and venting into the atmosphere, using the same technical equipment as described in RF patent No. 2549055, IPC A62C 3 / 00, A62C 3/00, publ. 04/20/2015.

Adjusting the DHW parameters after receiving a signal about the pre-fire pre-emergency state of the fire hazard source from the pre-emergency control means is carried out in a separate room in which the desired fire hazard source is located, sealing it and then adjusting the DHW parameters, or in the whole facility.

Creating, maintaining and adjusting the parameters of the domestic hot water can be done with the help of technical means (Fig. 1), proposed in RF patent No. 2549055, IPC A62C 3/00, A62C 3/00, publ. 04/20/2015.

The method is as follows.

The method is implemented using the technical means shown in FIG. one.

1. The initial parameters of the gas-air environment after sealing is set at:

- oxygen content of about 14% vol;

- DHW pressure - about 140 kPa;

- the partial pressure of oxygen is about 19.2 kPa;

- the rest - as for normal conditions.

The initial parameters of the gas-air medium are established by adding nitrogen from nitrogen cylinders 10 or by supplying air from node 9 of high pressure air cylinders (VVD) through node 13 of the membrane separation of air into nitrogen and oxygen, followed by utilization of excess oxygen by compressing it with compressor 8 of high pressure air into cylinders of the VVD or withdrawal from the facility. After establishing the initial parameters of the gas-air environment, their maintenance is provided by the node 4 regeneration of the gas-air environment and, if necessary, other technical means of the above.

Monitoring and control in this case is carried out by the node 3 of the sensors for monitoring the parameters of the hot water supply.

After submersion of the submarine in the case of the normal state and functioning of the ship’s technical facilities and equipment, the parameters of the hot water supply in the submarine’s premises do not change during the entire sealing period.

2. In the event that the transition of the gas-air medium, technical means or equipment of the submarine into the pre-emergency pre-fire condition detected by the node 2 of the pre-emergency control sensors is performed, the DHW parameters are adjusted in a separate sealed room in which the pre-emergency pre-fire condition is detected, or on the submarine as a whole.

Regulation is carried out in two ways (option 1 and 2).

Option 1 - by lowering the DHW pressure from 140 kPa to values of 101-120 kPa while maintaining the oxygen percentage at about 14% vol and lowering the partial pressure from 19.2 kPa to 13.8-16.8 kPa, which ensures compression of excess air compressor 8 into the cylinders of the VVD node 9 or removal of the object. Monitoring and control in this case is carried out by the node 3 of the sensors for monitoring the parameters of the hot water supply.

Option 2 - by regulating the oxygen content in the hot water supply with maintaining the hot water pressure at the initial level of about 140 kPa, with a decrease in oxygen concentration to 11-12 vol. % at a hot water supply pressure of 140 kPa, or about 15.5-17.2 kPa of partial oxygen pressure under normal conditions, for a time, usually 30-60 minutes, sufficient to search for a source of danger by separating air into oxygen and nitrogen by unit 13 membrane separation of air by removing excess oxygen-enriched mixture outside the object or compressing it with compressor 8 into the air cylinders of the VVD unit 9 while maintaining the hot water pressure by supplying nitrogen from cylinders with nitrogen 10 or air from the cylinders of the VVD unit 9.

Option 3 - combined control with a reduction in hot water pressure, partial oxygen pressure and oxygen concentration, which is a combination of the two control options described above with the achievement of oxygen concentration values brought to normal conditions, ensuring that a person is in them for 30-60 minutes without significant damage to his health and performance.

3. After identifying the source of fire danger in the pre-emergency pre-fire state and normalizing its state or shutting down, the initial parameters of the hot water supply are restored at the hot water pressure level of about 140 kPa and the partial oxygen pressure of about 19.2 kPa by supplying nitrogen from nitrogen from nitrogen cylinders 10, air from the cylinders of the VVD node 9 directly to the room or through the node 13 of the membrane separation of air to restore pressure and restore oxygen content, and also using the node 4 regeneration ha ovozdushnoy medium and, if necessary, other technical means of the above mentioned regulation and maintenance of the recovered WAN parameters.

The GHG regulation diagram corresponding to the claimed method is shown in FIG. 2, options 1 and 2.

The regulation in option 1 at stage I is carried out while maintaining the oxygen concentration, lowering the DHW pressure and, accordingly, lowering the partial pressure of oxygen, while the fire hazard index F _i at the facility decreases and the habitability index for the gas-air medium Q _i decreases (graphs P _{i parz} O _{2 start} and C _{i start} O ₂ , P _{iΣ start} , F _i and Q _i in Fig. 2, option 1, step I).

Further, in the next step (Fig. 2, option 1, step II), the partial oxygen pressure, the hot water supply pressure and oxygen concentration are maintained for a time sufficient to search for the source of fire hazard, at the level established after regulation, while maintaining the achieved level fire safety indicator F _i , and the level of dwellability index for hot water supply Q _i falls, approaching the minimum acceptable (Fig. 2, option 1, stage II).

After identifying the source of the fire hazard and the necessary actions to localize the threat of fire, the parameters of the hot water supply are restored to the initial values preceding the regulation (Fig. 2, option 1, stage III).

The regulation in option 2 at stage I is carried out with the preservation of hot water pressure, a decrease in oxygen concentration, and, accordingly, a decrease in the partial pressure of oxygen, while the fire hazard F _i at the facility decreases and the habitability index for the gas-air medium Q _i decreases (graphs P _{i parc} O _{2 beg} and C _{i beg} O ₂ , P _{iΣ beg} , F _i and Q _i in Fig. 2, option 2, step I).

Further, in the next step (Fig. 2, option 2, step II), the partial oxygen pressure, the hot water supply pressure and oxygen concentration are maintained for a time sufficient to search for the source of fire hazard, at the level established after regulation, while maintaining the achieved level fire safety indicator F _i , and the level of dwellability index for hot water supply Q _i falls, approaching the minimum acceptable (Fig. 2, option 2, stage II).

After identifying the source of the fire hazard and the necessary actions to localize the threat of fire, the parameters of the hot water supply are restored to the initial values preceding the regulation (Fig. 2, option 2, stage III).

The most effective and fast-acting method of fire control of hot water supply parameters, but more difficult to implement, is combined control with a decrease in hot water pressure, oxygen partial pressure and oxygen concentration, which is a combination of the two control options described above.

After the work program is completed at the end of the sealing, crew members decompress for about 15 minutes in the process of normalizing the DHW pressure at the facility to atmospheric pressure before depressurization.

Thus, the use of the claimed method allows to achieve increased fire safety of submarines and other similar sealed inhabited objects by creating gas-air media in them, which reduce the likelihood of fire ignition and spread, and at the same time makes it possible to ensure crew work for a long time without a significant decrease in working capacity and damage to health and without the need for special measures for subsequent decompression, and also ensures the preservation of the main x SP modes of operation and equipment performance.

Claims (2)

1. A method of increasing fire safety inside sealed inhabited objects, mainly submarines, including the use of an oxygen-nitrogen medium with an oxygen content of 14 ± 1 vol.% And maintaining increased air pressure for the entire time of sealing so that the partial pressure of oxygen in the medium matches normoxic and amounted to 20-21 kPa, and the pressure of the gas-air medium corresponded to 150 kPa, characterized in that the established parameters of the gas-air medium (DHW) are regulated for even greater to increase the fire safety of the facility for a given time, after receiving a signal from the means of pre-fire pre-emergency control about the transition of the fire hazard source to the pre-emergency pre-fire state, by reducing the hot water pressure and, accordingly, reducing the partial pressure of oxygen while maintaining the oxygen concentration, or by reducing the oxygen concentration, and, accordingly, reducing the partial pressure of oxygen while maintaining the hot water pressure, or a combination of both of these methods, moreover, established d.h.w. parameters during the entire cumulative regulation time should not be detrimental to health or significantly reduce the efficiency of crew members. 2. The method according to p. 1, characterized in that after sealing the initial parameters of the gas-air medium are established, characterized by an oxygen content of about 14 vol.%, A hot water supply pressure of about 140 kPa, a partial oxygen pressure of about 19.2 kPa and the rest of the parameters, as for normal conditions, and when regulating, in one embodiment, lower the DHW pressure from 140 kPa to 101-120 kPa while maintaining the percentage of oxygen at 13-14 vol.% and lowering the partial pressure from 19.2 kPa to 13.8-16 , 8 kPa, or, in another embodiment, support pressure DHW at the initial level of about 140 kPa and at the same time reduce the oxygen concentration to 11-12 vol.% at a hot water pressure of 140 kPa, or about 15.5-17.2 kPa of the partial pressure of oxygen under normal conditions, for a while, as a rule, 30-60 minutes, or combine both of the above versions of the method in such a way as not to damage the health and performance of the crew members, and after identifying the source of the fire hazard, the initial parameters of the gas-air environment are restored.

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