In order to prevent hydrogen from fire and explosion accidents, protect the lives of employees and prevent loss of state property, this standard specifies the safety technology for the use of hydrogen.
This standard is applicable to hydrogen supply stations, hydrogen supply devices and hydrogen supply operations where bottled hydrogen is a gas source.
The use of hydrogen gas in addition to the implementation of this standard, the other issues not specified, should still meet the requirements of the existing national norms, procedures.
1 Terminology
1.1 hydrogen supply station
The collective name between the bus bar, the real bottle room, and the empty bottle.
1.2 hydrogen supply device (or hydrogen supply system)
An assembly of equipment, pipes, and accessories for storing and delivering hydrogen.
1.3 Cylinders
The collective name of empty bottles and solid bottles.
1.4 real bottle
Gas cylinders under a certain filling pressure are generally calculated with a capacity of 40 liters of water and a pressure of 150 kgf/cm2.
1.5 empty bottles
No pressure or cylinder under a certain residual pressure.
1.6 Bottles
A combined unit of several cylinders fixed with a frame.
1.7 Vent tube
A facility that directly discharges hydrogen into the atmosphere.
1.8 Flame arrester
A safety device that prevents hydrogen from tempering.
1.9 Humid hydrogen
Hydrogen with a certain relative humidity that can reach saturation and precipitate moisture during transportation.
1.10 open fire location
There is a fixed place with exposed flames or red hot surfaces inside and outside.
1.11 Dissemination of Spark Locations
Fire-fighting chimneys or outdoor wheels, welding, gas welding, and electrical switches are equivalent locations.
2 hydrogen supply station
2.1 The general layout of the hydrogen supply station shall meet the following requirements.
2.1.1 The hydrogen supply station should be located at the edge of the plant area and the vehicle should be accessible to and from a convenient location as close to the main hydrogen site as possible.
2.1.2 The fire prevention spacing for the half-side of the hydrogen supply station should not be less than the following table.
Fireproof spacing table for hydrogen distribution station plane layout
name
Minimum fire separation, meters
Other buildings fire rating
First, second grade, third grade, fourth grade
12
14
16
Class A warehouse
20
Outside the house, substation
25
Civil construction
25
Important public buildings
50
Fire or Sparks Location
30
Mink type helium gas tank, meter 3
<500
501~10000
>10000
12
15
20
Sink type oxygen storage tank, rice 3
≥1000
>1000
10
12
Flammable liquid tanks, rice 3
1～50
51-200
201 to 1000
1001 to 5000
15
19
25
31
Flammable liquid tank
According to 5m3 flammable liquid equal to 1m3 flammable liquid equivalent
Coal and coke, tons
100 to 5000
>5000
6
8
Off-site railway (center line)
30
In-plant railway (center line)
20
Off-site roads (roadside)
15
The main road in the factory (roadside)
10
In-plant secondary road (roadside)
5
Note: 1 The fire separation distance between buildings is calculated according to the nearest distance to the adjacent exterior wall. If the outer wall has protruding burning objects, it shall be counted from the outer edge of the protruding part; the fire-proof spacing of tanks and transformers shall be calculated from the outer wall closest to the building.
2 The external walls of the oxygen supply station adjacent to other buildings are non-combustion bodies, and there are no doors, windows, holes and non-exposed burner housings, and the fire prevention distance can be reduced by 25% according to this table.
3 Fixed-capacity combustible gas storage tanks shall be carried out in accordance with the requirements of the tank tank storage tanks in accordance with the product of their water capacity (m3) and working pressure (kgf/cm2).
4 The fireproof distance between the hydrogen supply station and the overhead power line should not be less than 1.5 times the height of the utility pole.
2.2 The hydrogen supply station should use an independent single-story building, and its fire resistance rating should not be lower than Grade 2. Do not set up a hydrogen supply station in the basement or semi-basement of a building. When the number of solid bottles does not exceed 60 bottles, it can be connected with a hydrogen plant with a fire resistance rating of not less than two, or a factory with a fire resistance class of not less than two, but the adjacent building should be connected. It is a firewall with no doors, windows or holes.
2.3 The explosion-proof design of the plant for the hydrogen supply station shall be carried out in accordance with the relevant provisions of TJ16-74 "Failure to Build a Fire Protection Code for Buildings" (Trial). The ratio of pressure relief area to room volume should not be less than its upper limit.
2.4 The height of the lower chord of the roof of the hydrogen supply station should not be less than 4 meters (the height of the container station should not be less than 6 meters).
2.5 The roof should be made into a flat structure to prevent the accumulation of hydrogen dead corner. The floor is as flat, wear-resistant and spark-free as possible. It is as high as the loading platform.
2.6 The layout of bus rooms, empty bottles and solid bottles shall meet the following requirements:
2.6.1 The bus bays, empty bottles and solid bottles should be set separately (except for the container station). The busbars can communicate with each other through the door opening or between empty bottles or solid bottles, but each must have its own entrance.
2.6.2 When the number of solid bottles does not exceed 60 bottles, the empty bottles, solid bottles and bus bars may be arranged in the same room. However, the solid bottles and empty bottles shall be stored separately. The net distance between empty (real) bottles and bus bars should not be less than 2 meters.
2.6.3 Busbars, empty bottles, and solid bottles should not be directly connected to the instrument room, power distribution room, and living room. Use firewalls without doors, windows, and holes to separate them. For connectivity, a double doorway shall be provided, the door shall be automatically closed (eg, spring door), and the fire limit shall not be less than 0.9 hours.
2.6.4 There should be brackets, fences and other facilities for preventing the inversion of the bottles between empty bottles and solid bottles.
2.6.5 The net width of the passages between bus bars, empty bottles and solid bottles shall be determined according to the handling mode of the gas cylinders, generally not less than 1.5 meters.
2.6.6 The bus bar should be as spacious as possible. The bus bar should be arranged against the wall, and the frame of the gas cylinder should be fixed.
2.6.7 Shade measures shall be provided in the solid bottles to prevent direct sunlight from entering the bottles.
2.6.6 The cylinder loading and unloading platform should be provided between the empty bottles and the real bottles. The height of the platform is determined by the gas cylinder transportation tool, which is generally 0.4 to 1.1 meters above the outdoor floor and the width of the platform is 1.5 to 2 meters. The awnings and supports on the platform should be made of non-combustible materials.
Bunker station should be equipped with explosion-proof lifting facilities.
2.7 The interior must be well-ventilated and the maximum content of hydrogen in the air must not exceed 1 % (volume ratio).
The upper part of the building or the upper part of the external wall has no louvers (buildings) or vents. Vent holes should be oriented towards safe areas, indoor air changes shall not be less than three times per hour, and accident ventilation shall not be less than seven times per hour.
2.8 The selection, wiring and grounding of electrical equipment are to comply with the relevant provisions of the State's "Electrical Safety Regulations for Explosive Hazardous Locations".
2.9 The hydrogen supply station should have lightning protection measures.
2.10 According to the provisions of GB2894-82 "Safety Signs" set fire prohibition signs around the hydrogen supply station.
3 hydrogen supply device
3.1 Hydrogen bottles
Without counting hydrogen cylinders, manufacturing and inspection should comply with the requirements of the “Cylinder Safety Supervision Regulationsâ€.
3.2 Collection bottles
3.2.1 The total weight per unit must not exceed 2 tons. The safety factor of assembly fixtures and rings must not be less than 9. Gas cylinders, pipes, valves and joints shall be fixed. No loose movement shall be allowed. Pipes and valves shall be protected against collision.
3.2.2 The main pipeline should have two valves in series. Each cylinder should have sub-valves.
3.3 Fixed gas storage tank
3.3.1 Gas tanks should be equipped with vent valves, safety valves and pressure gauges. Where the maximum working pressure is greater than or equal to 1 kgf/cm2, its design, manufacture and inspection shall comply with the requirements of the Pressure Vessel Safety Supervision Regulations.
3.3.2 The foundation and support of the gas storage tank must be strong and non-combustion.
3.3.3 The surface of the gas storage tank should be higher than the ground of the production units of Category A and B that emit combustible gas and flammable vapours. Otherwise, the physical enclosure wall with a height of not less than 1m shall be provided for isolation.
3.3.4 The fireproof spacing of the plane arrangement of gas storage tanks shall be implemented in accordance with the relevant provisions of TJ16-74 for the fireproof spacing of flammable gas storage tanks.
3.4 Pipeline
3.4.1 Pipes and accessories should be selected in accordance with the national standard product, and should be suitable for hydrogen working pressure and temperature requirements.
Hydrogen pipelines should adopt seamless metal pipelines, and the use of cast iron pipelines is prohibited.
3.4.2 Pipe connections should generally be welded or other effective means of preventing air leakage.
3.4.3 Venting tube, sampling port and purge port shall be provided on the pipeline, and the position shall be able to meet the requirements of gas purging and replacement in the hip tract.
3.4.4 When hydrogen is used for welding, cutting, fuel, protective gas, etc., flame arrestors shall be provided on the branch pipes of each hydrogen unit.
3.4.5 Pipe laying shall meet the following requirements:
3.4.5.1 Hydrogen pipelines are to be laid overhead. Their supports shall be non-burning bodies. Overhead pipelines should not be laid on the same bracket as cables and conductive lines.
When the hydrogen pipeline and the gas pipeline i oxygen pipeline are laid in parallel, the non-combustible material pipeline shall be separated or the net distance shall not be less than 250 mm in the middle. When laying layers, the hydrogen pipeline should be located above.
Hydrogen pipelines and buildings. The minimum distance between structures or other pipelines can be implemented with reference to the regulations.
3.4.5.2 Indoor pipelines shall not be laid in the trench or buried directly. The pipelines laid in outdoor trenches shall have measures to prevent hydrogen leakage, accumulation or intrusion into other trenches. The depth of buried pipelines should not be less than 0.7 meters. Pipes containing moist hydrogen should be laid below the frozen layer.
3.4.5.3 Pipes shall be installed through walls or floors. The pipe section in the casing should not have a weld seam, and the pipeline and casing should be filled with non-combustible materials.
3.4.5.4 Piping shall be avoided through trenches, sewers, and railway car roads. When necessary, casing shall be provided.
3.4.5.5 Pipes must not pass through living rooms, offices, power distribution rooms, instrument rooms, stairwells, and other rooms that do not use hydrogen. Should not pass through the ceiling, technical (clamp) layer, when must pass through the ceiling or technical (clip) layer, should take safety measures.
3.4.6 Pipes and busbars laid on indoor or outdoor overhead or buried ground and its connected gas cylinders shall be connected to each other and grounded. The crossover and grounding measures shall be implemented in accordance with the relevant national regulations.
3.5 Vent tube
3.5.1 The vent valve shall be provided for the vent valve, safety valve and piping system of the hydrogen tank.
3.5.2 The vent tube should be made of metal. No plastic tube or rubber tube is allowed.
3.5.3 The venting pipe shall be provided with a flame arrester. Where conditions permit, it may be connected with fire-extinguishing steam or inert gas pipeline to prevent ignition.
3.5.4 The exit of the indoor vent pipe should be more than 2 meters above the roof. The emptying pipe for outdoor equipment should be more than 2 meters above the highest equipment in operation nearby.
3.5.5 The vent tube should be grounded with static electricity and within the scope of lightning protection.
3.5.6 Measures shall be taken to prevent the intrusion of rain and snow and foreign material to block the vent tube.
4 Hydrogen System Operation Safety Points
4.1 The oxygen content of the input system must not exceed 0.5%.
4.2 During the operation of the cyanogen system, tapping is not allowed, pressure repair and tightness are not allowed, no overpressure is allowed, and negative pressure is strictly prohibited.
4.3 When pipes, valves and water seals are frozen, they can only be thawed with hot water or steam, and baking with open flames is strictly forbidden.
4.4 Leakage check of connecting points of equipments, pipelines and valves, etc. Soap water or portable flammable gas explosion-proof detectors may be used, and open flames shall be prohibited.
4.5 Do not vent hydrogen indoors. Purge replacement, venting and depressurization, must be vented via vent tube.
4.6 When a large amount of hydrogen gas leaks or accumulates, the air source should be cut off immediately and ventilated, and all operations that may generate sparks may not be performed.
4.7 The newly installed or overhauled hydrogen system must be subjected to pressure test, cleaning and air tightness test, and meet the relevant inspection requirements before it can be put into use.
4.8 Hydrogen system purging and replacement, generally nitrogen (or other inert gas) replacement method or water injection exhaust method.
Nitrogen replacement method should meet the following requirements:
4.8.1 The oxygen content in nitrogen must not exceed 3%.
4.8.2 Replacement must be thorough to prevent residual air at the dead ends.
4.8.3 After the end of the displacement, the content of oxygen or hydrogen in the system must pass three consecutive analyses.
4.9 When the hydrogen system is overhauled, it must be ensured that the maximum content of hydrogen within the system and the hot zone does not exceed 0.4%.
4.10 Prevent open flames and other sources of energy. It is forbidden to use electric stoves, electric drills, stoves, torches, etc. to produce open flames, high-temperature tools and hot objects; no fire shall be allowed to enter the fire-fighting area; copper or beryllium-copper alloy tools shall be used. l Wear cotton overalls and anti-static shoes.
5 hydrogen bottle use
5.1 Due to production needs, cylinders must be used on site (indoor), the number of which shall not exceed 5 bottles, and shall meet the following requirements:
5.1.1 ventilation conditions with 2.7.
5.1.2 The distance between hydrogen bottles and containers containing flammable, explosive, combustible substances and oxidizing gases and cylinders should not be less than 8 meters.
5.1.3 The distance to open fire or general electrical equipment should not be less than 10 meters.
5.1.4 The spacing between air inlets for air conditioning units, air compressors and ventilation equipment should not be less than 20 meters.
5.1.5 The spacing from other flammable gas storage sites should not be less than 20 meters.
5.1.6 Supports with fixed cylinders.
5.1.7 The use of cylinders in multi-storey buildings, except for special production needs, should generally be arranged on the top floor at the outer wall.
5.2 The use of gas cylinders is forbidden for knocking and collision; it must not be near heat sources; summer exposure should be prevented.
5.3 A dedicated pressure reducer must be used. When opening, the operator should stand behind the valve port and the movement should be gentle.
5.4 When the valve or pressure reducer leaks, do not continue to use it; when the valve fq is damaged, it is forbidden to replace the valve with pressure inside the bottle.
5.5 The use of gas in the bottle is strictly forbidden. Remaining pressure of 0.5 kgf/cm2 or more is to be retained.
6 fire fighting
6.1 The hydrogen supply station shall set fire-fighting water according to relevant regulations of TJ16-74, and shall be equipped with portable fire extinguishing equipment such as "dry powder", "1211" and "carbon dioxide", or nitrogen and steam extinguishing systems as required.
6.2 Hydrogen fire should take the following measures:
6.2.1 cut off the gas source.
6.2.2 cooling, isolation, to prevent the fire from expanding.
6.2.3 Maintain the hydrogen system positive pressure to prevent tempering.
6.3 Hydrogen flames are not noticeable. Ambulance personnel should prevent exposed skin burns.