Refrigerant explosion mechanism May-2016 - AHI Carrier … · GENERAL INFORMATION ATEX = Explosive...
Transcript of Refrigerant explosion mechanism May-2016 - AHI Carrier … · GENERAL INFORMATION ATEX = Explosive...
Refrigerant explosion
mechanism
COMPANY CONFIDENTIAL
May-2016
COMPANY CONFIDENTIAL
REFRIGERANT EXPLOSION MECHANISM
•General information
•Flammability characteristics
•Ignition sources
•Consequences of explosions
Summary
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GENERAL INFORMATION
ATEX = Explosive Atmosphere
FuelCombustion
agent
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Gas, vapour, mist and dusts
Oxygen in the air or chemical products
Electric arc, electrostatic or mechanical spark, hot
surfaces or flames, etc.
GENERAL INFORMATION
Fuel: can burn
Combustion agent: facilitates
combustion
Ignition source: initiates combustion
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FLAMMABILITY CHARACTERISTICS
LEL UEL
Explosive range
0%
100% 0%
100%
FLUIDS EXPLOSIVE RANGE
R1234ze(E) 6.5% Explosive ...%
R32 13% Explosive 33%
HRD103 9.9% Explosive …%
MAINS GAS 5% Explosive 15%
Fuel
Combustion
agent
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FLAMMABILITY CHARACTERISTICS
Example: Machine containing 400kg of R1234ze(E)
fluid (LEL=6.5%) in room (400m3)
= An explosion is possible in the room if an ignition source is present
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Case of a massive leak in the room(not @safety relief valves)
=
=
Air/fuel concentration in the room:
21% of R1234ze(E)
FLAMMABILITY CHARACTERISTICS
Concept of ATEX zones
(explosive atmospheres)
Emission source
Concentration
(LEL↔UEL)
Probability
Duration
EXPLOSIVE
AREA
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FLAMMABILITY CHARACTERISTICS
Concept of ATEX zones
(explosive atmospheres)
EXPLOSIVE
AREA
A location in which an explosive atmosphere is either permanently
present, or present for long periods of time, or frequently presentZone 0
A location in which it is likely that a gaseous explosive atmosphere
will occasionally occur during normal operationZone 1
A location in which a gaseous explosive atmosphere is not likely to
occur in normal operation but which, if it does, will only persist for
a short length of time.
Zone 2
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FLAMMABILITY CHARACTERISTICS
Concept of ATEX zones
(explosive atmospheres)
Zone 2: rare
Zone 0:
Permanent
Zone 1:
occasional
EXPLOSIVE
AREA
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10
Flammable liquid
'X' tank
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Zone 0
Zone 1
Zone 2
Example of ATEX zones choice
FLAMMABILITY CHARACTERISTICS
FLAMMABILITY CHARACTERISTICS
Example of ATEX zones on the CARRIER site
EXPLOSIVE AREA:
zone 2
0.5 m
0.5 m
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IGNITION SOURCES
The ignition sources:
One-off ,ie: Sparks PERMANENT, ie:Hot surfaces
Minimum ignition
energy (MIE):
< 300 µJ 'example'
Autoignition
temperature
(368°C for R1234ze,
530°C for R32)
Example:
Static electricity
produced by the
human body > 5mJ
Example:
Brazing flame 700°C< Temp.< 1000°C
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SH
OR
T L
AS
TIN
G T
IME
LO
NG
LA
ST
ING
TIM
E
R1234ze
~ 60 mJ
IGNITION SOURCES
Example of ignition sources:
Electricity (power
equipment,
instrumentation on the
machine, in the room)
Static electricity
(insulating material,
humans, floors, etc.)
Mechanical impact
(machines and
structures, tools)
Flames and hot
surfaces (soldering
& brazing work,
etc.)
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CONSEQUENCES OF EXPLOSIONS
Impact on people: each year, the industry experiences
• about 1500 explosions
• about 500 injured, 20 fatalities
Economic and social impact: loss of equipment and facilities, loss of jobs
Environmental impact: release of toxic products into the environment
Explosion of a gas
Video
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