GB/T 29729-2013 English PDF (GB/T29729-2013)

GB/T 29729-2013: Essential requirements for the safety of hydrogen systems
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GB/T 29729-2013
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.020; 71.100.20
G 86
Essential requirements for the safety of hydrogen
systems
(ISO/TR 15916:2004, Basic considerations for the safety of hydrogen
systems, NEQ)
ISSUED ON: SEPTEMBER 18, 2013
IMPLEMENTED ON: JANUARY 01, 2014
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of PRC;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3 
1 Scope ... 4 
2 Normative references ... 4 
3 Terms and definitions ... 6 
4 Types of hydrogen systems ... 6 
5 Basic characteristics of hydrogen ... 7 
6 Hazard factors of hydrogen system ... 8 
7 Risk control ... 10 
Appendix A (Informative) Typical hydrogen production system ... 31 
Appendix B (Informative) Nature of hydrogen ... 35 
Appendix C (Informative) Combustion characteristics of hydrogen ... 39 
Appendix D (Informative) Commonly used metal materials in hydrogen
environment ... 41 
Essential requirements for the safety of hydrogen
systems
1 Scope
This standard specifies the categories of hydrogen systems, the basic
characteristics of hydrogen, the risk factors of hydrogen systems, the basic
requirements for risk control.
This standard applies to the design and use of hydrogen production, storage
and delivery systems.
2 Normative references
The following documents are essential to the application of this document. For
the dated documents, only the versions with the dates indicated are applicable
to this document; for the undated documents, only the latest version (including
all the amendments) are applicable to this standard.
GB 2894 Safety signs and guideline for the use
GB 4962-2008 Technical safety regulation for gaseous hydrogen use
GB 5099 Seamless steel gas cylinders
GB 12014 Static protective clothing
GB 12358 Gas monitors and alarms for workplace General technical
requirements
GB 16808 Combustible gas alarm control units
GB/T 18442.1 Static vacuum insulated cryogenic pressure vessels - Part 1:
General requirements
GB/T 18442.2 Static vacuum insulated cryogenic pressure vessels - Part 2:
Materials
GB/T 18442.3 Static vacuum insulated cryogenic pressure vessels - Part 3:
Design
GB/T 18442.4 Static vacuum insulated cryogenic pressure vessels - Part 3:
3 Terms and definitions
The terms and definitions as defined in GB/T 24499 as well as the following
terms and definitions apply to this document.
3.1
Hydrogen system
Hydrogen production, storage or delivery system.
3.2
Limit of detonation
The concentration range of flammable and explosive gas, steam or dust in
air/oxygen that can cause detonation explosive gas mixture.
3.3
Thermal stratification
The fluid stratification phenomenon in which the cold fluid is at the bottom
and the hot fluid is at the top, in the direction of gravity, due to the different
fluid density as caused by the different temperature.
3.4
Hydrogen storage in solid state
A method of hydrogen storage that chemically reacts with hydrogen in the
form of a solid substance or physically adsorbs it.
3.5
Confined space
A space with restricted access, poor ventilation, and danger.
4 Types of hydrogen systems
4.1 Hydrogen production system
The hydrogen production system mainly includes water electrolysis hydrogen
production system, fossil energy hydrogen production system, renewable
energy hydrogen production system. The fossil energy hydrogen production
system mainly includes natural gas steam conversion hydrogen production
5.2.2 The detonation limit of hydrogen in normal temperature and pressure air
is 18.3% ~ 59% (volume fraction); the detonation velocity is 1480 m/s ~ 2150
m/s.
6 Hazard factors of hydrogen system
6.1 Leakage and seepage
6.1.1 Hydrogen easily leaks through porous materials, assembly surfaces or
sealing surfaces. After the hydrogen leaks, it will diffuse rapidly, resulting in the
continuous expansion of combustible and explosive areas, meanwhile the
diffusion process is invisible to the naked eye. The main factors affecting
hydrogen leakage and diffusion include leakage location, ambient temperature,
ambient wind speed, ambient wind direction and obstacles.
6.1.2 After the leakage of the liquid hydrogen and hydrogen slurry system, the
liquid hydrogen and hydrogen slurry will quickly evaporate and diffuse, forming
a visible explosive mist, which may cause the system to form a negative
pressure and cause the surrounding air to enter the system to condense and
freeze, blocking the pipes, valves and other components of the system.
6.1.3 Hydrogen easily penetrates into some non-metallic materials and causes
hydrogen leakage. If hydrogen leakage occurs in the liquid hydrogen or
hydrogen slurry system, it can lead to hydrogen loss or damage to the vacuum
insulation layer.
6.2 Hazard factors related to combustion
6.2.1 If hydrogen, liquid hydrogen or hydrogen slurry is ignited, it will cause
hydrogen to burn or explode. Hydrogen combustion can cause deterioration of
the material properties of the hydrogen system, which may cause the hydrogen
system to fail due to a sharp increase in internal temperature and pressure.
6.2.2 Hydrogen deflagration can lead to the rapid expansion of the combustion
area and the rapid increase of the pressure in the confined space. The high-
speed detonation wave produced by hydrogen detonation can have a huge
impact on the environment outside the combustion zone, meanwhile it is
accompanied by the rapid propagation of high-temperature gas.
6.3 Hazard factors related to pressure
6.3.1 The failure of the hydrogen system can cause the rapid release of high-
pressure hydrogen storage energy, forming a shock wave, destroying
surrounding facilities.
6.3.2 The heat leakage of the liquid hydrogen and hydrogen slurry system will
the steel to form methane, causing steel decarburization and the formation of
microcracks, resulting in irreversible deterioration of steel properties. The
higher the temperature and the greater the hydrogen partial pressure, the more
severe the hydrogen corrosion of steel.
6.6.2 After the metal absorbs internal hydrogen or external hydrogen, when the
local hydrogen concentration reaches saturation, it will cause a decrease in
plasticity, induce cracks or delay fracture. The higher the temperature, the
greater the hydrogen partial pressure, the greater the strain rate, the more
serious the hydrogen embrittlement of the metal.
6.7 Physiological hazards
6.7.1 Human skin directly contacting low-temperature hydrogen, liquid
hydrogen or hydrogen slurry can cause frostbite; direct contact with high-
temperature hydrogen flames that are invisible to the naked eye can easily
cause high-temperature burns.
6.7.2 The large amount of ultraviolet radiation produced by hydrogen
combustion is easy to damage human skin; the secondary fire caused by
hydrogen fire can produce dense smoke or other harmful combustion products,
which endanger human health.
7 Risk control
7.1 Basic principles
The hydrogen system shall follow the following basic principles:
a) Under the premise of meeting demand, control the amount of hydrogen
used in storage and operation;
b) Develop corresponding operating procedures;
c) Reduce the number of people in hazardous environments and shorten
their time;
d) Avoid the accumulation of hydrogen/air (oxygen) mixture in confined
spaces;
e) Determine the explosion hazard area of the hydrogen system; the grade
definition of the explosion hazard area shall meet the requirements of GB
50058;
f) Ensure that there are no other debris in the explosion hazard area of the
hydrogen system and the passage is unblocked.
good low temperature toughness; its ductile brittle transition temperature shall
be lower than the operating temperature of the system.
7.2.2.3 The non-metallic materials used in the hydrogen system shall have good
resistance to hydrogen penetration.
7.2.2.4 When the shape or size of the material changes due to temperature or
pressure changes, the deformation between adjacent materials shall be
coordinated with each other, to ensure the sealing performance of the system
and the normal operation of each component.
7.2.2.5 Metal materials in direct contact with hydrogen in the hydrogen system
shall have good compatibility with hydrogen. When necessary, the hydrogen
compatibility test shall be carried out on the material within the temperature and
pressure range equivalent to the conditions of use.
7.2.2.6 For the hydrogen system, steel with low carbon content or strong
carbide forming elements should be selected.
7.2.2.7 Refer to Appendix D for commonly used metal materials in hydrogen
environment. In order to reduce the hydrogen embrittlement sensitivity of metal
materials, the following measures shall be taken:
a) Control the hardness and strength of the material at an appropriate level;
b) Reduce residual stress;
c) Avoid or reduce cold plastic deformation of materials;
d) Avoid fatigue failure of components subjected to alternating loads;
e) Use materials with low hydrogen embrittlement sensitivity such as
austenitic stainless steel and aluminum alloy.
7.2.3 Equipment
7.2.3.1 Hydrogen storage container
7.2.3.1.1 When designing hydrogen storage containers, full consideration shall
be given to the influence of atmospheric environmental temperature conditions
on the metal temperature of the container shell under normal working conditions;
the minimum design metal temperature shall not be higher than the lowest value
of the monthly average lowest temperature over the years .
7.2.3.1.2 The support and foundation of the hydrogen gas storage container
shall be non-combustible and secure; the grounding requirements of the
container shall comply with the provisions of 9.0.7 in GB 50177-2005.
to prevent explosion caused by static electricity.
7.2.3.2.4 The coating and transportation packaging of stationary liquid
hydrogen storage containers, mobile liquid hydrogen storage containers and
their parts shall comply with the provisions of JB/T 4711 and the technical
requirements of drawings.
7.2.3.2.5 The material selection, design, manufacturing, inspection and testing,
safety and protection of stationary liquid hydrogen storage containers shall
comply with the relevant provisions and standards such as TSG R0004, GB/T
18442.1 ~ 6.
7.2.3.2.6 The material selection, design, manufacture, inspection and testing of
mobile liquid hydrogen storage containers shall comply with relevant provisions
and standards such as TSG R0005, "Supervision provisions for safety of gas
cylinders".
7.2.3.2.7 The design of low-temperature insulated gas cylinders shall comply
with the relevant provisions and standards such as the "Supervision provisions
for safety of gas cylinders".
7.2.3.3 Hydrogen slurry storage container
In addition to the requirements of 7.2.3.2, the hydrogen slurry storage container
shall also meet the following requirements:
a) Prevent pollutants from entering the container; promptly dispose of the
solid hydrogen particle accumulation in the container;
b) Replenish or concentrate the hydrogen slurry in time, to ensure that the
mass fraction of solid hydrogen in the container meets the requirements.
7.2.3.4 Solid hydrogen storage container
In addition to the requirements of 7.2.3.1.4, 7.2.3.1.5 and 7.2.3.1.7, solid
hydrogen storage containers shall also meet the following requirements:
a) Prevent local accumulation of solid fillers during use;
b) The tube ends of the single tube or the tube shall be equipped with a filter
with a filtration accuracy that matches the particle size of the solid
hydrogen storage material;
c) Depending on the hydrogen storage capacity and the thermal effect of
solid hydrogen storage, the solid hydrogen storage container should be
designed as a heat exchanger structure.
7.2.3.5 Compressor
and shall not be laid on the same support with cables, conductive lines,
high-temperature pipelines;
g) When hydrogen pipelines are laid together with other pipelines or
arranged in layers, the hydrogen pipelines should be arranged on the
outside and placed on the upper layer; a certain safe distance shall be
maintained;
h) Pipes and buildings, structures or other pipelines shall maintain a certain
safe distance; indoor pipelines shall not be laid in trenches or directly
buried in the ground; outdoor pipelines laid in trenches; measures shall be
taken to prevent hydrogen leakage and accumulation.
7.2.4.2 Hydrogen pipeline
7.2.4.2.1 The laying of hydrogen pipelines in hydrogen stations, hydrogen
supply stations and workshops shall comply with the provisions of clause
12.0.10 in GB 50177-2005; when hydrogen pipelines are laid overhead, directly
buried in the ground and laid in open trenches, they shall comply with the
provisions of 12.0.11, 12.0.12 and 12.0.13 in GB 50177-2005; when hydrogen
pipelines are laid together with other pipelines or arranged in layers, they shall
comply with the provisions of 4.4.6 in GB 4962-2008.
7.2.4.2.2 Vent pipes, analysis sampling ports and purge replacement ports shall
be provided on the hydrogen pipeline; their positions shall meet the
requirements of gas discharge, sampling, purge and replacement in the pipeline.
7.2.4.3 Liquid hydrogen and hydrogen slurry pipeline
7.2.4.3.1 The pipeline insulation shall adopt high-vacuum multilayer insulation,
vacuum powder insulation or other insulation methods with excellent thermal
insulation effect.
7.2.4.3.2 When using a corrugated expansion joint, it shall be placed in a
vacuum jacket; the piping system shall have sufficient flexibility to avoid thermal
expansion and contraction causing pipeline failure or leakage.
7.2.4.3.3 Threaded connection shall not be used.
7.2.4.3.4 The liquid hydrogen and hydrogen slurry pipelines shall be provided
with safety relief devices where liquid m...