Section
5 Materials, equipment and components
5.1 Materials
5.1.2 The materials within the fuel cell power installation shall be suitable
for the intended application and are to comply with recognised International or
National Standards.
5.1.3 The use of combustible materials within the fuel cell power system shall
be kept to a minimum.
5.1.5 Pipes, valves and other components for the containment of hydrogen or
hydrogen rich gas are to be constructed of austenitic stainless steel. Other
materials are subject to special consideration where they can be demonstrated to:
- be resistant to the chemical and physical action of hydrogen at the
operating conditions, including consideration of hydrogen embrittlement and
hydrogen attack;
- be suitable for the intended application, including consideration of
hydrogen permeability, static accumulation and sparking;
- have hydrogen compatibility in accordance with a recognised International or
National Standard (e.g. ASME B31.12 Hydrogen Piping and Pipelines); and
- comply with any specifications and test procedures considered necessary by
LR.
5.2 Piping and pressurised equipment and components
5.2.1 In addition to the fuel cell specific requirements within these Rules,
where fuel cell power installations incorporate piping components included in Pt 5, Ch 12 Piping Design Requirements, they are to satisfy the
corresponding requirements therein.
5.2.2 All pipes containing reformed fuel for fuel cell power systems, where
fitted, shall:
- not be led through enclosed spaces outside
of fuel cell spaces;
- be fully welded as far as practicable;
- be arranged to minimise the number of
connections; and
- use fixed hydrogen detectors which are
capable of detecting a hydrogen leak in places where leakage of hydrogen may
occur, such as valves, flanges and seals.
5.2.3 Piping sections containing fuel which are not open ended but can be
isolated are to be provided with relief valves. Alternative arrangements may be
considered where an equivalent level of safety can be demonstrated.
5.2.4 The design pressure is the maximum permissible working pressure and is to
be not less than the highest set pressure of the safety valve or relief valve. In no
case is the design pressure to be less than 10 barg except for open-ended piping
where the minimum design pressure is to be 5 barg.
5.2.5 The design pressure of feed piping and other piping on the discharge from
pumps is to be taken as the pump pressure at full rated speed against a shut valve.
Where a safety valve or other protective device is fitted to restrict the pressure
to a lower value than the shut valve load, the design pressure is to be the highest
set pressure of the device.
5.2.6 Low temperature piping is to be thermally isolated from the adjacent hull
structure, where the piping temperature can be lower than the design temperature of
the hull.
5.2.7 Piping is to demonstrate electrical continuity and be earth bonded to the
hull.
5.2.8 Heat exchangers and evaporators are to be designed to prevent
cross-contamination between the primary and secondary sides of the heat exchanger
and are to incorporate an alarm and fuel supply shutdown in the event of
cross-contamination.
5.2.9 Pumps are to be protected against running dry and protected against
overpressure in the event that downstream lines are blocked, or downstream valves
are closed.
5.2.10 Where connections and non-welded joints for piping are required, they are
to be of an approved type and are to:
- be resistant to the chemical and physical
action of hydrogen at the operating conditions, including consideration of
hydrogen embrittlement and hydrogen attack;
- be suitable for the intended application,
including consideration of hydrogen permeability, static accumulation and
sparking;
- demonstrate hydrogen compatibility in
accordance with a recognised International or National Standard (e.g. ASME
B31.12 Hydrogen Piping and Pipelines); and
- comply with any specifications and test
procedures considered necessary by LR.
5.3 Mechanical equipment and components
5.3.1 In addition to the fuel cell specific requirements within these Rules,
where fuel cell power installations incorporate mechanical equipment and components
included in Pt 5 Main and Auxiliary Machinery, they are to satisfy the
corresponding requirements therein.
5.3.2 Mechanical equipment is not to be installed in hazardous areas unless
essential for operational purposes or safety enhancement.
5.3.3 The design, arrangements and selection of mechanical equipment and
components for use in hazardous areas are to minimise sources of ignition.
5.3.4 Mechanical equipment and components intended for use in a hazardous area
are to be designed, constructed and installed to ensure that they are:
- capable of safe operation in normal and all reasonably foreseeable hazardous
conditions;
- capable of preventing the formation of a hazardous and/or toxic atmosphere
that may be produced or released by the components or equipment;
- capable of preventing the ignition of hazardous atmospheres, taking into
account the nature of every electrical and non-electrical source of
ignition; and
- appropriate for use in a hazardous area in accordance with a
recognised International or National Standard, such as ISO 80079-36
Non-electrical equipment for explosive atmospheres — Basic method and
requirements
5.4 Electrical equipment and components
5.4.1 In addition to the fuel cell specific requirements within these Rules,
where fuel cell power installations incorporate electrical equipment and components
included in Pt 6, Ch 2 Electrical Engineering, they are to satisfy the
corresponding requirements therein.
5.4.2 Electrical equipment shall not be installed in hazardous areas unless
essential for operational purposes or safety enhancement.
5.4.3 Where electrical equipment including components of fuel cell power
systems is installed in hazardous areas, it is be selected, installed and maintained
in accordance with recognised International or National Standards such as IEC
60079-10 Explosive atmospheres Part 10-1: Classification of areas – Explosive gas
atmospheres and guidance and informative examples given in IEC 60092-502,
Electrical Installations in Ships – Tankers – Special features for
tankers
5.4.4 In order to facilitate the selection of appropriate electrical apparatus
and the design of suitable electrical installations, hazardous areas are divided
into Zones 0, 1 and 2, according to Pt 5, Ch 26, 5.4 Electrical equipment and components 5.4.5.
In cases where the prescriptive provisions in Pt 5, Ch 26, 5.4 Electrical equipment and components 5.4.5
are deemed to be inappropriate, area classification according to IEC 60079-10
Explosive atmospheres – Part 10-1: Classification of areas – Explosive gas
atmospheres shall be applied with special consideration by LR and the
Administration.
5.4.5 Definition of zones
- Hazardous areas Zone 0. The following areas should be treated as
hazardous area Zone 0:
the interiors of buffer tanks, reformers, pipes
and equipment containing low-flashpoint fuel or reformed fuel, any
pipework of pressure-relief or other venting.
- Hazardous areas Zone 1. The following areas should be treated as hazardous
area Zone 1:
- areas on open deck or semi-enclosed spaces on deck within 3 m of any
reformed fuel or purge gas outlets or fuel cell space ventilation
outlets;
- areas on open deck, or semi-enclosed spaces on deck, within 3 m of
fuel cell exhaust air and exhaust gas outlets;
- areas on open deck or semi-enclosed spaces on deck within 1,5 m of
fuel cell space entrances, fuel cell space ventilation inlets and
other openings into Zone 1 spaces;
- areas on open deck or semi-enclosed spaces within 3 m of areas in
which other sources of release of reformed fuel are located;
and
- fuel cell spaces.
- Hazardous areas Zone 2. The following areas should be treated as hazardous
area Zone 2:
- areas within 1,5 m surrounding open or semi-enclosed spaces of Zone
1 as specified above, if not otherwise specified; and
- air locks.
5.4.6 Ventilation ducts are to have the same area classification as the
ventilated space.
5.4.7 For fuel cell spaces rated as hazardous Zone 1 where the fuel cell stack
is not certified for operation in hazardous Zone 1 and the surface temperature of
the fuel cell stack exceeds 300°C, the fuel cell power system should immediately
shut down and isolate the affected fuel cell space
5.5 Monitoring, control, alarm and safety system equipment and components
5.5.1 In addition to the fuel cell specific requirements within these Rules,
where fuel cell power installations incorporate monitoring control, alarm and safety
systems, equipment and components included in Pt 6, Ch 1 Control Engineering Systems, they are to satisfy the
corresponding requirements therein.
5.5.3 The fuel cell shall be monitored appropriately to avoid any loss or
degradation of its safety.
5.5.4 All operating conditions are to be monitored to verify that they are
within the acceptable design range.
5.5.5 A Failure Mode and Effects Analysis (FMEA) shall be used to analyse and
determine the extent of monitoring and control of the fuel cell power systems. The
following shall be included as a minimum:
- voltage of fuel cells;
- temperature of exhaust gas and exhaust air;
- the internal temperature of the fuel cell. When the internal temperature
reaches 80 per cent of the self-ignition temperature for the reformed fuel
used, the load of the fuel cell shall be disconnected or reduced, or other
cooling measures shall be taken;
- purity of the reformed fuel;
- output current; and
- contamination of air into fuel cell fuel lines, or of fuel cell fuel into
air pipes.
5.5.6 The following monitoring shall be considered according to the type and
working condition of the fuel cell:
- air flow;
- air pressure;
- flow rate, pressure and temperature of cooling medium;
- fuel flow;
- fuel temperature;
- fuel pressure;
- gas detection of exhaust fuel and exhaust air;
- liquid level of water system;
- pressure of water system;
- resistivity/conductivity of the water system;
- parameters necessary to monitor life time/deterioration of fuel cell; and
- balancing the air-to-fuel ratio in operation.
5.5.7 The fuel cell shall be provided with fault monitoring sensors to maintain
the reaction process within the design limits.
5.5.8 A permanently installed gas/vapour detection system shall be provided
for:
- fuel cell spaces;
- airlocks (if any);
- expansion tanks/degassing vessels in the auxiliary systems of the fuel cell
power system where primary fuel or reformed fuel may leak directly into a
system medium (e.g. cooling water); and
- other enclosed spaces where primary/reformed fuel may accumulate.
- Ventilation outlets, if required, as per Pt 5, Ch 26, 5.5 Monitoring, control, alarm and safety system equipment and components 5.5.9.
5.5.9 The detection systems shall continuously monitor for gas/vapour. The
number of detectors in the fuel cell space shall be considered taking size, layout
and ventilation of the space into account. The detectors shall be located where
gas/vapour may accumulate and/or in the ventilation outlets. Gas dispersal analysis
or a physical smoke test shall be used to find the best arrangement.
5.5.10 Gas/vapour detection shall be provided in the fuel cell’s coolant
supply/header tank, and this should cause an alarm.
5.5.11 Gas/vapour detection shall be provided at the process air outlet exhaust,
and this should cause an alarm.
5.5.12 Gas/vapour detection shall be provided in the inter-barrier spaces, and
this should cause an alarm.
5.5.13 Two independent gas detectors located close to each other are required
for redundancy reasons. If the gas detector is of the self-monitoring type, the
installation of a single gas detector can be permitted.
5.5.14 Manual activation of emergency shutdown shall be arranged in the
following locations as applicable:
- navigation bridge;
- onboard safety centre;
- engine control room;
- fire control station; and
- adjacent to the exit of the fuel cell space.
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