A.5.2.1.2 Instrumentation
Instrumentation of the enclosure is as described in A.5.1.1.2.
A.5.2.2 Fuel specification
A.5.2.2.1 Test pans
Specification of test pans is as described in A.5.1.2.1.
A.5.2.2.2 n-Heptane
See A.5.1.2.2.
A.5.2.2.3 Fire construction and placement
The test can filling requirements and placement within the enclosure are as described in A.5.1.2.1.
A.5.2.3 Test procedure
A.5.2.3.1 General
Prior to commencing tests the composition of the extinguishing aerosol shall be analysed.
A.5.2.3.2 Operation
The n-heptane filled test pans are to be ignited and allowed to burn for 30 s with the closeable openings above in the open position.
After 30 s all openings are to be closed and the extinguishing system is to be manually actuated. At the time of actuation of the system, the amount of oxygen within the enclosure shall not be more than 0,5 vol% lower than the normal atmospheric oxygen concentration. During the test, the oxygen concentration shall not change more than 1,5 vol% due to fire products. This change shall be determined by comparing the oxygen concentration measured in the cold discharge test with the measured oxygen concentration in this test (averaged over the three sensors).
A.5.2.3.3 Results recording
Results are to be recorded as specified in A.5.1.3.3.
A.5.2.4 Determination of distribution performance of the generator
Using the extinguishing factor for heptane, determined according to A.6.2, all test pans have to be extinguished within 30 s after the end of agent discharge.
A.6 Extinguishing factor tests
A.6.1 Wood crib test
A.6.1.1 Test facility
A.6.1.1.1 Construction
The test enclosure shall meet the following requirements:
the test enclosure shall have a minimum volume of 100 m3. The height shall be at least 3,5 m. The floor dimensions shall be at least 4 m wide by 4 m long;
means of pressure relief shall be provided;
the temperature in the test enclosure shall be (20 ± 5) °С at the beginning of each test and there shall be enough time between the tests so that the enclosure can adapt to this temperature.
A.6.1.1.2 Instrumentation
Sampling and storage of data from the sensors described below shall occur at a rate of at least 4 Hz.
A.6.1.1.3 Oxygen concentrations
The oxygen level shall be measured by a calibrated oxygen analyser capable of measuring the percentage oxygen to within at least one decimal place (0,1 %). The sensing equipment shall be capable of continuously monitoring and recording the oxygen level inside the enclosure throughout the duration of the test. The accuracy of the measuring devices shall not be influenced by any of the fire products.
At least three sensors shall be located within the enclosure (Figures A.5 and A.6). One sensor shall be located at the equivalent height of the top of the test object from the floor, 0,6 m to 1 m away from the test object. The other two sensors shall be located at 0,1 x H and 0,9 x H (with H = height of the enclosure (see Figures A.5 and A.6).
A.6.1.1.4 Discharge pressure
The pressure built up during system discharge shall be recorded by pressure transducer at a distance not greater than 1 m. from the discharge outlet.
A.6.1.1.5 Enclosure temperature
Temperature sensors shall be located centred 100 mm above the test object and 0,9 x/7 (/-/ = room height), and a third sensor at the equivalent height of the top of the test object from the floor, horizontally 0,6 m to 1 m away from the test object (see Figures A.5 and A.6).
NOTE It is recommended to use К type thermocouples (Ni-CrNi), diameter 1 mm.
A.6.1.1.6 Aerosol temperature and discharge times
A thermocouple shall be placed just outside the discharge outlet of the aerosol generator to record aerosol temperature at the outlet as well as commencement and end of aerosol discharge. Additional thermocouples may be placed at the minimum thermal clearance from the discharge outlet as specified by the manufacturer for each unit size of the aerosol generators.
NOTE It is recommended to use К type thermocouples (Ni-CrNi), diameter 1 mm.
A.6.1.1.7 Flame out times
Cameras, e.g. infrared-cameras, or an alternative means of directly viewing the fire can be provided as an aid to determining flame out times.
Figure A.5 — Plan view of instrumentation placement for the extinguishing factor test
A.6.1.2 Fuel specification
A.6.1.2.1 Crib igniter fuel
Ignition of the crib is achieved by burning 1,5 I of commercial grade n-heptane (specified in A.5.1.2.2) on a 12,5 I layer of water in a square steel pan 0,25 m2 in area, 100 mm in height and with a wall thickness of 6 mm (see Figure A.7).
500mm
Figure A.7 — Pan geometry for wood crib and n-Heptane pan fire test
A.6.1.2.2 Fire configuration and placement
The wood crib is to consist of four layers of six, approximately 40 mm x 40 mm by (450 ± 50) mm long, kiln spruce or fir lumber having a moisture content between 9 % and 13 %. Place the alternate layers of wood members at right angles to one another. Evenly space the individual wood members in each layer forming a square determined by the specified length of the wood members. Staple or nail together the wood members forming the outside edges of the crib.
The crib shall be pre-burned outside the enclosure on a stand supporting the crib 300 mm above the pan holding the igniter fuel (specified in A.6.1.3.1).
After the pre-burn period the crib shall be moved into the enclosure and be located on a stand supporting the crib centrally within the enclosure with the base of the crib 600 mm above the floor (specified in A.6.1.3.1).
A.6.1.3 Test procedure
A.6.1.3.1 General
Prior to commencing tests, the composition of the extinguishing aerosol shall be analysed. Record the mass and the moisture of the crib prior to the test.
A.6.1.3.2 Operation
Centre the crib with the bottom of the crib approximately 300 mm above the top of the pan on a test stand constructed so as to allow for the bottom of the crib to be exposed to the atmosphere. The pre-burning shall take place outside the enclosure, if possible in a sufficiently dimensioned room (at least five times the volume of the test enclosure). In any case, the pre-burning shall not be influenced by weather conditions such as rain, wind, sun. The maximum wind speed in the proximity of the fire shall be 3 m/s. If necessary, adequate means for protection against wind etc. shall be used. Record the weather conditions including location of pre-burn, air temperature, humidity and wind speed.
Ignite the n-heptane and allow the crib to burn freely. The 1,5 1 of n-heptane will provide a burn time of approximately 3 min. After the n-heptane is exhausted, the crib shall be allowed to burn freely for an additional time of 3 min resulting in a total pre-burn time of (6 ) min outside the test enclosure.
Just prior to the end of the pre-burn period, move the crib into the test enclosure and place it on a stand such that the bottom of the crib is 600 mm above the floor. Seal the enclosure and actuate the system. The time required to position the burning crib in the enclosure and the actuation of the system discharge shall not exceed 15 s.
At the time of actuation of the system, the amount of oxygen within the enclosure at the level of the crib shall not be more than 0,5vol% lower than the normal atmospheric oxygen concentration. During the test, the oxygen concentration shall not change more than 1,5vol% due to fire products. This change shall be determined by comparing the oxygen concentration measured in the cold discharge test with the oxygen concentration measured in this fire test (averaged values).
From the end of system discharge, the enclosure is to remain sealed for a total of 10 min. After the soak period, remove the crib from the enclosure and observe to determine that sufficient fuel remains to sustain combustion and for signs of re-ignition.
The following shall be recorded:
presence and location of burning embers;
whether or not the glowing embers or crib re-ignites;
mass of the crib after the test.
If necessary, amend the aerosol extinguishing factor and repeat the experimental programme until three successive, successful extinguishments are achieved.
A.6.1.3.3 Results recording
After the required pre-burn period, record the following data for each test:
discharge time of extinguishant, in seconds;
time required to achieve extinguishment, in seconds. This time shall be determined by visual observation, thermocouples readings or other suitable means;
soaking time (time from the end of system discharge until the opening of the test enclosure);
recording the temperature profile of the wood crib, using the infrared camera, is recommended.
A.6.1.4 Determination of extinguishant design factor
The laboratory extinguishing factor is that which achieves satisfactory extinguishment of the fire over three successive tests (no re-ignition or existence of burning embers after 10 min after end of discharge). The design factor is the laboratory extinguishing factor multiplied by an appropriate 'safety factor’ (1.3).
Extinguishing factor shall be calculated dividing the total mass of aerosol compound installed by the test room volume.
A.6.2 n-Heptane pan test
A.6.2.1 Test facility
A.6.2.1.1 Construction
Construction of the enclosure is as described in A.6.1.1.1.
A.6.2.1.2 Instrumentation
Instrumentation of the enclosure is as described in A.6.1.1.2.
A.6.2.2 Fuel specification
A.6.2.2.1 n-Heptane
See A.5.1.2.2.
A.6.2.2.2 Fire configuration and placement
The fire will be a square steel pan of 0,25 m2, 100 mm high with a wall thickness of 6 mm as specified in A.6.1.2.1. The test pan is to contain 12,5 I of n-heptane. The resulting n-heptane surface is then 50 mm below the top of the pan.
The steel pan shall be located in the centre of the test enclosure with the bottom 600 mm above the floor of the test enclosure.
A.6.2.3 Test procedure
A.6.2.3.1 General
Prior to commencing tests, the composition of the extinguishing aerosol shall be analysed.
A.6.2.3.2 Operation
The n-heptane is to be ignited and allowed to burn for 30 s.
After 30 s all openings are to be closed and the extinguishing system is to be manually actuated. At the time of actuation of the system, the amount of oxygen within the enclosure shall not be more than 0,5 vol% lower than the normal atmospheric oxygen concentration. During the test, the oxygen concentration shall not change more than 1,5 vol% due to fire products. This change shall be determined by comparing the oxygen concentration measured in the cold discharge test with the oxygen concentration measured in this fire test (averaged values).
If necessary, amend the extinguishant extinguishing factor and repeat the experimental programme until three successive, successful extinguishments are achieved.
A.6.2.3.3 Results recording
Results are to be recorded as specified in A.6.1.3.3 with the exception of d).
A.6.2.4 Determination of extinguishant design factor
The laboratory extinguishing factor is that which achieves satisfactory extinguishment of the fire over three successive tests (no flaming 30 s after the end of extinguishant discharge). The design factor is the laboratory extinguishing factor multiplied by an appropriate safety factor.
Extinguishing factor shall be calculated dividing the total mass of aerosol compound installed by the test room volume.
A.6.3 Polymeric sheet fire test
A.6.3.1 Test facility
A.6.3.1.1 Construction
Construction of the enclosure is as described in A.6.1.1.1.
A.6.3.1.2 Instrumentation
Instrumentation of the enclosure is as described in A.6.1.1.2.
A.6.3.2 Fuel specification
A.6.3.2.1 Igniter fuel
The ignition source is a heptane pan (constructed of 2 mm thick mild or stainless steel) with inside to inside 51 mm x 112 mm and 21 mm deep centred 12 mm below the bottom of the plastic sheets of polymeric fuel (see Figure A.8). The 51 mm side of the pan is orientated parallel to the sheets of polymeric fuel. The pan is filled with 6,0 ml of commercial grade heptane (specified in A.6.1.2.2) on a water base of 40 ml.
A.6.3.2.2 Polymeric fuel
Tests are to be conducted with three plastic fuels:
Polymethyl methacrylate (PMMA);
Polypropylene,
Acrylonitrile-butadiene-styrene polymer (ABS).
Plastic properties are given in Table A.2.
Table A.2 — Plastic properties
25 kW/m2Exposure in Cone Calorimeter - ISO 5660-1 Cone Calorimeter Test
|
Fuel |
Colour |
Density |
Ignition Time |
180 s average |
effective |
||||||
|
Heat Release Rate |
Heat of Combustion |
||||||||||
|
g/cm3 |
s |
Tolerance |
kW/m2 |
Tolerance |
MJ/kg |
Tolerance |
|||||
|
PMMA |
Black |
1,19 |
77 |
30% |
286 |
25% |
23,3 |
25% |
|||
|
Polypropylene |
Natural (White) |
0,905 |
91 |
30% |
225 |
25% |
39,6 |
25% |
|||
|
ABS |
Natural (Cream) |
1,04 |
115 |
30% |
484 |
25% |
29,1 |
25% |
|||
A.6.3.2.3 Polymeric fuel array
The polymeric fuel array shall consist of 4 sheets of polymer, which are cut to 405 mm ± 5 mm high by 200 mm ± 5 mm wide. The thickness of the sheets shall be as follows:
Polymethyl methacrylate (PMMA) - (9,0 ± 0,5) mm;
Polypropylene (PP) - (9,5 ± 0,5) mm;
Acrylonitrile-butadiene-styrene polymer (ABS) - (10,0 ± 0,5) mm.
Sheets are spaced and located as per Figure A.8. The bottom of the fuel array is located 203 mm from the floor. The fuel sheets shall be mechanically fixed at the required spacing. The sheets of plastic shall not significantly bend during the test.
The fuel array shall be located centrally within the enclosure.
A.6.3.2.4 Fuel shield
A fuel shield consisting of a metal frame with sheet metal on the top and two sides shall be provided around the fuel array as indicated in Figure A.8. The fuel shield is 380 mm wide, 850 mm high and 610 mm deep. The 610 mm (wide) x 850 mm (high) sides and the 610 mm x 380 mm top are metal sheet. The two remaining sides and bottom are open.
The metal sheet shall be aluminium with a wall thickness of 2 mm to 3 mm.
The fuel array is oriented in the fuel shield such that the 200 mm dimensions of the fuel array is parallel to the 610 mm side of the fuel shield.
A.6.3.2.5 External baffles
External baffles are constructed as shown in Figure A.9 and are located around the exterior of the fuel shield. The baffles are placed 90 mm above the floor. The top baffle is rotated 45° with respect to the bottom baffle.
A.6.3.3 Test procedure
A.6.3.3.1 General
Prior to commencing tests the composition of the extinguishing aerosol shall be analysed. Record the mass of the plastic sheets prior to the test.
A.6.3.3.2 Operation
The n-heptane is ignited and allowed to burn completely. 210 s after ignition of the n-heptane, all openings are to be closed and the extinguishing system is to be manually actuated.
At the time of actuation of the system, the amount of oxygen within the enclosure at the level of the fuel shall not be more than 0,5vol% lower than the normal atmospheric oxygen concentration. During the test, the oxygen concentration shall not change more than 1,5vol% due to fire products. This change shall be determined by comparing the oxygen concentration measured in the cold discharge test with the oxygen concentration measured in this fire test (averaged values).
The enclosure is to remain sealed for a total of 10 min from end of discharge. After the soak period, ventilate the enclosure and observe to determine that sufficient fuel remains to sustain combustion and for signs of reignition. The following shall be recorded:
presence and location of burning fuel;
whether or not the fire re-ignites; and
mass of the fire structure after the test.
If necessary, amend the extinguishing factor and repeat the experimental programme until three successive, successful extinguishment are achieved.
A.6.3.3.3 Results recording
After the required pre-burn period, record the following data for each test:
discharge time of extinguishant, in seconds;
time required to achieve extinguishment, in seconds. This time shall be determined by visual observation, thermocouples readings or other suitable means;
soaking time (time from the end of system discharge until the opening of the test enclosure).
A.6.3.4 Determination of design extinguishant factor
The laboratory extinguishing factor for each fuel is that which achieves satisfactory extinguishment of the fire over three successive tests (no flaming 60 s after end of discharge and no re-ignition after 10 min from end of discharge).
The design factor is the highest of the laboratory extinguishing factors for the three fuels (see A.6.3.2.2) multiplied by an appropriate safety factor.
Extinguishing factor shall be calculated dividing the total mass of aerosol compound installed by the test room volume.CEN/TR 15276-1:2009 (E)
Key
A Channel metal frame covered with metal sheet on top and two sides В Metal angle frame
C 1/8" All thread rod fuel support
D Drip tray
E Load cell
F Heptane pan
G Spacer
Figure A.8 — Polymeric sheet and composite wood panels fir
e
41
A Polycarbonate or metal baffles В Cinder block
Figure A.9 — Polymeric and composite wood panels fire baffle arrangement
A.6.4 Composite wood fire test
A.6.4.1 Test facility
A.6.4.1.1 Construction
Construction of the enclosure is as described in A.6.1.1.1.
A.6.4.1.2 Instrumentation
Instrumentation of the enclosure is as described in A.6.1.1.2.
A.6.4.2 Fuel specification
A.6.4.2.1 Igniter fuel
The ignition source is a n-heptane pan (constructed of 2 mm thick mild or stainless steel) 51mm x 112mm and 21 mm deep centred 12 mm below the bottom of the composite wood sheets (see Figure A.8). The 51 mm side of the pan is orientated parallel to the sheets of composite wood. The pan is filled with 12 ml of commercial grade n-heptane (specified in A.6.1.2.2), heptane will provide a burn time of approximately 3 min.
A.6.4.2.2 Composite wood
Tests are to be conducted with three composite woods:
Reformed wood (chops) both sides plastic lined;
MDF (Medium Density Fibreboards) according to EN 622 and EN 316 not lined;
Multilayers plywood ( kiln spruce or fir) not lined.
Composite wood properties are given in Table A.5.
Table A.5 — Composite wood properties
25 kW/m2Exposure in cone calorimeter - ISO 5660-1 cone calorimeter test
|
Fuel |
Colour |
Density |
Ignition Time |
180 s Average |
Effective |
|||
|
Heat Release Rate |
Heat of Combustion |
|||||||
|
g/cm3 |
s |
Tolerance |
kW/m2 |
Tolerance |
MJ/kg |
Tolerance |
||
|
Reformed wood (chops) both sides plastic lined |
White |
0,783 |
213 |
30% |
61,86 |
25% |
10 |
25% |
|
Reformed wood (chops) both sides unlined |
Brown |
0,882 |
109 |
30% |
65,56 |
25 % |
8,76 |
25% |
|
MDF (Medium Density Fibre boards) according to EN 622 and EN 316 not lined |
Brown |
0,886 |
91 |
30 % |
62,23 |
25 % |
9,33 |
25% |
|
Multi-layers plywood (kiln spruce or fir) not lined |
Brown |
0,991 |
93 |
30% |
60,33 |
25 % |
11,3 |
25% |
