determination of concentration time curves of the
TRANSCRIPT
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DMT GmbH & Co. KG
Plant- and Product Safety
Product Assessment
Air Conditioning and Air Quality
Am Technologiepark 1
D-45307 Essen, Germany
Telefon +49 201 172-1304
Telefax +49 201 172-1606
www.dmt-group.com/de
TÜV NORD GROUP
Determination of concentration time
curves of the refrigerant R290 in leakage
simulations on multideck cabinets
- - - - - - - - - - - - - - - - - - -
Report APS 2 – 00 005 16
CUSTOMER
Deutsche Umwelthilfe e.V.
Hackescher Markt 4
10178 Berlin
Consultant
DR. DANIEL COLBOURNE
PO Box 4745
Stratford upon Avon
Warwickshire
CV37 1FE
Examined Specimen
AHT, VENTO
Carrier, Optimer 2546
Examination performed by
Simon Roeser, Philip Pawlinski
Dr. Dirk Renschen
Order No
RK 20658672
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CONTENT PAGE
1 INITIAL SITUATION ...................................................................................................... 3
2 SPECIMEN (MULTIDECK CABINETS) ......................................................................... 3
3 TEST SET UP, TESTING EQUIPMENT AND TEST METHOD ..................................... 4
3.1 TEST FACILITY ..................................................................................................................... 4
3.2 TEST EQUIPMENT ................................................................................................................ 9
3.3 TEST PROCEDURE ............................................................................................................ 14
3.3.1 Test setup in the tent ....................................................................................................... 14 3.3.2 Placement of the nozzles for the leakage simulation ...................................................... 18 3.3.3 Testing scheme................................................................................................................ 21
3.4 SAFETY - EXPLOSION PROTECTION .............................................................................. 22
4 EXAMPLES OF TEST RESULTS ................................................................................23
4.1 EXAMPLE RESULTS OF TEST RUN 1 .............................................................................. 23
4.2 REPEATABILITY OF THE R290 CONCENTRATION MEASUREMENTS ........................ 27
4.3 PRESENTATION OF ALL TEST RESULTS ........................................................................ 32
5 SUMMARY ...................................................................................................................33
ANNEX 1A ...........................................................................................................................34
ANNEX 1B ...........................................................................................................................35
ANNEX 2..............................................................................................................................36
ANNEX 3..............................................................................................................................37
ANNEX 4..............................................................................................................................52
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1 Initial situation
DMT GmbH & Co. KG as independent testing institution was commissioned by the non-
profit association “Deutsche Umwelthilfe e.V.”, Berlin, to perform a series of tests with
multideck cabinets and R290 ( R290) as refrigerant. These examinations with chiller or
multideck cabinets were carried out in February and March 2016.
R290 has excellent thermodynamic properties leading to high energy efficiency and a
low environmental impact. But it has some different chemical properties than fluorocar-
bon refrigerants; the primary difference is its classification as high flammability (A3) ac-
cording to ISO 817.
As a basis for detecting the risk of explosion in the operation of such filled R290 cooling
systems leakage simulation tests with R290 shall be performed by DMT. In defined
rooms of different sizes determinations of the concentration time curves of the refrigerant
R290 ( R290) shall be carried out within leakage simulations. Concentrations of R290
shall be put into relation to the lower explosion limit (LFL).
This Report describes exemplary the test procedure executed.
2 Specimen (Multideck cabinets)
Two different types of multideck cabinets were to be tested (picture 1a & b).
The first type was from (company) AHT (Austria), a “VENTO HYBRID” plug-in multideck
chiller with following sizes: length 375 cm, height 238 cm and shelf width 126 cm.
Picture 1a) AHT VENTO HYBRID cabinet
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This cabinet has a top-mounted condensing unit.
The second type was from Carrier, an “Optimer 2546” plug-in refrigerated multideck cab-
inet with following sizes: length 250 cm, height 199 cm and shelf width 85 cm.
Picture 1b) Carrier “Optimer 2546” plug-in refrigerated multideck cabinet
3 Test set up, testing equipment and test method
To examine the leakage behaviour of cabinets with R290 as natural refrigerant main tar-
get was to create a test setup which ensures a (repeatable and) reproducible test proce-
dure. Therefore, these tests were performed as leakage simulations in a purpose-built
tent with the opportunity to create variable room sizes for the different tests. This tent
was set up inside a hall to keep the environmental conditions quite constant. For all tests
the same sensors and test conditions were used. In the following the details are de-
scribed.
3.1 Test facility
Testing was performed in a tent inside of a hall with outer dimension of 32 m length,
11.8 m width and roughly 9 m height (drawing in pic. 2a). The tent was set up in the front
part of the hall (designation “E01” in pic. 2). The dimensions of the tent were 10 m x 4 m
x 2.5 m (l x w x h). A drawing of the tent (upper part – top view; lower part – view longitu-
dinal side) is shown in picture 2b. With the help of a “partition wall” within the tent the dif-
ferent room sizes could be realized (10 m², 20 m² & 40 m²).
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Picture 2a) Sketch of Test Hall B1, Horizontal Projection
The building has a folding gate in the front (bottom line of the sketch).
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Picture 2b) Sketch of tent (upper part – top view; lower part – view longitudinal side)
The total volume of the tent was 100 m³. The rigid construction of the tent was made from
square-shaped timber; the walls of the tent were made from 0.4 mm PE foil which was
fixed to the timbers and gas tight. The foil intersections were air tight glued with heavy in-
dustrial tape. The tent had two zipper doors, one zipper door on each broad side. The
closed zippers showed no visual gaps against bright light. Therefore, the “basic” assem-
bly was gas tight. Nevertheless, to be able to ventilate the tent for air exchange between
the tests in the roof a hole was cutted (pic. 4g). This hole was covered with a coalescer
filtermedia as cover and convection blocker. The leakage gases R290 and CO2 are
heavier than air. As long as there is no ventilation (or convection) in the tent, there will be
no significant gas loss.
Photos from the test hall and tent are shown in pictures 3a to 3h.
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Pic. 3a) Test hall: front view
Pic. 3b) Test hall: back and side view
Pic. 3c) Test hall front with open front door and
tent long side
Pic. 3d) Tent long side with look behind the
zipper door of the test tent
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Pic. 3e) View from outside the hall to the
tent front with cabinet in between
Pic. 3f) Inside tent with view to front and
cabinet
Pic. 3g) Tent roof
Pic. 3h) Tent back side with view to rolling
door on the right side of the test
hall
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3.2 Test Equipment
The following measurement and testing equipment components were used for the leak-
age simulation tests:
- Test gas R290 from a pressurized bottle (pic. 4a). Within testing a primary pres-
sure of 5 bars was adjusted by the pressure-relief valve.
- Calibrated mass flow controller (MFC) Series 358 (pic. 4b). It is a „DIGITAL
PRESSURE REGULATOR” from company ANALYT-MTC GmbH for dosage of the
R290 gas.
o Volume rate control and measurement was done with a calibrated mass
flow controller (which uses the differential drop across a laminar flow ele-
ment for determination the exact flow rate).
o Volume rate range: 0 to 100 l/min
o Gas selection between 20 different gases
o Calibration includes R290 and CO2
o Precision: ± 0.2 % Full scale
o Response time: ≤ 100 ms
Calibration of the mass flow controller for R290 was verified by DMT: After a
release of 3 x 300 g of R290 according the MFC the pressurized gas bottle lost
900 g (± 10 g).
Within testing there were no indications that at the measurement point (MFC)
the R290 was not totally transformed to the gas phase.
- “Nozzle to simulate leakage of a tubing”
Nozzles were used to release R290 in the cabinet to simulate a leakage in a tubing
of the refrigerant circle. They generated a gas stream comparable to the situation
when a leakage occurs by a fissure in a tubing. The different nozzles were built
from brass with a drilled hole. Diameters of the different nozzles were: 0.7; 1.0; 1.5
& 2.0 mm (pic. 4c).
- R290 measurements at different locations within the tent were performed with:
10 calibrated IR-sensors (GfG, Dortmund, Germany; pic. 4d – left side)
o Intrinsically safe IR transmitter for explosion protection
o ATEX II 1G Ex ia IIC T4 Ga C0158 (can be used in Ex zone 0)
o Temperature, moisture and pressure compensation
o Patented 4-beam 4-wavelength technology
o Measuring range: 0 to 100 % LFL (lower explosion limit)
o Gas supply: Diffusion through membrane
o Repeatability: ≤ 0.5 % of measurement range
and up to 10
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Thermal conductivity sensors (FTC 220, Messkonzept, Frankfurt, Germany;
pic. 8d – right side)
o Response time < 10 s
o Measuring range: 0 … 6 Vol. %
o Repeatability: ≤ 1 % of measurement range
- Data Aquisition
Each IR-sensor was connected with an ATEX-box (safe power supply for the sen-
sor). Theses boxes were located outside of the tent and connected to an A/D con-
verter which again was plugged via a LAN connection to a personnel computer in-
stalled in the control room below the test hall (pic. 8e).
- Ventilation of the tent (Removal of R290)
After end of a test run the „ R290-contaminated“ air from the tent was sucked out of
the tent by an explosion proof fan (TFV 100 radial fan EX) and blown in the envi-
ronment outside of the test hall (pic. 4f).
Fresh air was sucked in the tent through a hole in the roof, which was covered by a
coalescer filter-media as blocker for thermal convection (pic. 4g)
Pic. 4a) Control room with two laptops, pressur-
ized R290 bottles and further test
equipment
Pic. 4b) Calibrated mass flow controller
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Pic. 4c) “Simulated leakages tubes” (Nozzles)
Pic. 4d) Two Calibrated Sensors for R290
measurement
Pic. 4e) Blue boxes “ATEX-box”, Red box in the
lower part “A/D converter”
Pic. 4f) TFV 100 radial fan EX
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Pic. 4g) Hole in the roof with coalescer filter
(white) as cover and convection blocker
All components to release R290 in the cabinets (Pressurized R290 bottle, mass flow control-
ler and nozzle) were connected by flexible, pressure stable and tight tubes. The mass rate of
R290 which was released was controlled by the MFC via the A/D-converter which was con-
trolled from a laptop. The IR-sensors were controlled and the data acquired from the same
laptop. The thermal conductivity sensors (FTC) were controlled and its data acquired by a
further laptop. The connection scheme is shown below in figure 1.
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Figure 1) Connection scheme for R290 leakage simulation tests
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3.3 Test procedure
3.3.1 Test setup in the tent
A comparable test setup for both cabinets was planned.
The test setup for the sensors should be as shown in figure 2.
Figure 2) Positioning of the test cabinet (grey) and the sensors (red) in a test room
In this figure the positions are shown schematically. “Floor” means sensor was posi-
tioned on the floor level and e.g. “room centre, 1 m” that the sensor was positioned in
the room centre in 1 m height by means of a tripod.
The sensor position “Beneath unit, 1 m (when applicable)” was deleted because there
was no sufficient space for the ATEX-proved sensors.
The first type cabinet had a top-mounted condensing unit (“VENTO HYBRID” from
AHT) and a size (l x h x w) of 375 cm x 238 cm x 126 cm. Due to this very big dimen-
sions for this cabinet it could only be tested in the 20 m² and 40 m² room sizes.
First it was positioned with its back to the wall in the centre of the broad side to the
test room (pic. 5a). Afterwards it was equipped with shelfs and filled with boxes to
simulate the conditions in a supermarket (pic.5b).
In this picture 5b the tripod can be seen in front of the cabinet and equipped with 3
sensors (see pic. 4d): on floor level (blue IR sensor), 1 m (grey FTC sensor) and 2 m
(again FTC). In this picture ropes can be seen which were used for test 21 (Annex 1,
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test matrix), when two doors in the middle were opened 1min after start of leakage
simulation (pic. 5c).
Some tests were made with a simulated roof top cover (pic. 5d) to examine the effect
of such covers.
Cabinets were maximally loaded to minimise internal free volume and thus lead to
pessimistic scenario (e.g. pic. 5b).
All tests were made without operation of the refrigerator. For some tests fans were in
operation to examine the effect of mixing the R290 with the room air.
Pic. 5a) Cabinet with a top-mounted condensing unit as delivered
Pic. 5b) Cabinet with a top-mounted condensing unit before testing
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Pic. 5c) Cabinet as in pic. 5b but closer
Pic. 5d) Again cabinet with top-mounted condensing unit but with roof cover
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The test setup for testing the Carrier “Optimer 2546” plug-in refrigerated multideck
cabinet was comparable (pic. 6a). Due to the smaller size of this cabinet with base-
mounted condensing unit (l x h x w: 250 cm x 199 cm x 85 cm) tests could be per-
formed in the 10 m² test room, too (pic. 6b).
Pic. 6a) Cabinet with base-mounted condensing unit in the 20 m² test room (broad side)
Pic. 6b) Cabinet with base-mounted condensing unit in the 10 m² test room (narrow side)
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3.3.2 Placement of the nozzles for the leakage simulation
The different types of nozzles which were used for the leakage simulations are shown
in picture 4c (nozzles of different drill hole sizes).
Preparing the different tests each time a nozzle had to be positioned as described in
the test matrix to the according leak locations in both cabinets.
In pictures 7a - d the installation of the nozzles in the Carrier cabinet with base-
mounted condensing unit are shown.
Pic. 7a) Cabinet Base CU with CRB
(condenser return bend), RH
(right hand) Leakage Point
Pic. 7b) Cabinet Base CU with ERB
(evaporator return bend), RH,
before installation
Pic. 7c) Cabinet Base CU with ERB
(evaporator return bend), RH,
with installed nozzle (center)
and supply pipe on right side
Pic. 7d) Cabinet Base CU with ERB
(evaporator return bend) and
nozzle behind cover
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In pictures 8a - 8f the installation of the nozzles in the AHT cabinet with top-mounted
condensing unit are shown.
Pic. 8a) Cabinet Top CU with CRB
(condenser return bend) RH
(right hand) Leakage Point
Pic. 8b) Cabinet Top CU with CRB
(condenser return bend) RH
(right hand) Leakage Point
Pic. 8c) Cabinet Top CU with nozzle
located in the CU unit (center)
Pic. 8d) Cabinet Top CU, the supply
pipe of the nozzle enters
the unit through the hole in
the cover (upper part)
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Pic. 8e) Cabinet Top CU with ERB
with installed nozzle (center)
and supply pipe entering the
housing from the bottom
Pic. 8f) Cabinet Top CU with ERB
(evaporator return bend)
In pictures 9a & b the installation of a nozzle in a mock-up (cardboard box) on the top
of the Carrier cabinet (base-mounted condensing unit) is shown. This mock-up was
used for leakage simulations in a top CU in the 10 m² room.
Pic. 9a) Carrier cabinet (Base CU) with
mock-up as a top CU unit from
cardboard, supply pipe on the
right
Pic. 9b) Mock-up unit from cardboard,
nozzle in the center (iron
weight on the right to load the
mock up
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3.3.3 Testing scheme
The testing schemes were developed from discussions amongst DMT, DUH,
D. Colbourne and IEC SC61C WG4.
In table 1) the different variables or parameters of both test matrix are summarized
with the used values or descriptions.
Remark: *) In parentheses are numbers of fans used for testing
Table 1) Variables of the test matrix
Between the tests the tent was ventilated (contaminated air extracted) for air ex-
change. The extraction was monitored and stopped at a R290 LEL level of ≤ 1 %.
The individual test matrix for the AHT top CU cabinet and the Carrier base mounted
CU cabinet measurements are shown in Annex 1 and 2.
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3.4 Safety - Explosion protection
To avoid any explosion within testing several general precautions and countermeasures
were made. Base of these precautions and countermeasures was an expert’s report to
explosion prevention (Report 20658672: Explosionsschutzkonzept gemäß § 6 (9) 2. Gef-
StoffV für einen Versuchstand zur Untersuchung von Leckageszenarien an Kühlgerä-
ten). This expert report was made by the specialists of the DMT department “Fire and
explosion protection”.
This expert’s report included:
Review and Assessment of Material Properties
Measures to prevent hazardous explosive atmospheres
Precautions against ignition
Measures for reduction of explosion effects to a safe level
Organizational explosion protection measures
Examples of precautions and countermeasures for explosion protection:
Several thermal conductivity measurement sensors were placed around the tent
to monitor a possible leakage of R290 in the surrounding. Alert level were indi-
cated automatically in the control room.
No persons stayed in the test hall during the measurements.
The control office was located one floor below the test hall.
Access of unauthorized and untrained persons was prohibited.
The released amount of R290 was controlled continuously by online monitoring
the concentration in the tent by the test personnel.
Manual closing of the R290 supply and start of the extraction of R290 from the
tent after fault-related test stop or completion of test from the control room.
Avoidance of electrostatic charges within testing (no opening of the zipper doors
before air extraction after completion of test).
Use of fans for the multideck cabinets were built classified as „II 2 G Ex d e ib IIB
T3 Gb“.
A risk assessment of the manufacturer of the fan was made for this leakage test.
People involved in testing were instructed how to behave according the explosion
protection rules listed in expert report.
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4 Examples of test results
All test measurement results from the different sensors were collected in excel sheets. The
R290 concentrations were transformed to %-values of the according lower explosion level
(LFL) from R290 (propane: 2.1 % v/v; NFPA). For each test run these transformed data of all
sensors were written for the same time scale in one excel-sheet. All raw data were given
from DMT to the consulter of DUH for further data analysis.
4.1 Example results of test run 1
Before a test run was started all parameters were adjusted as described in the example from
the following table 2 (extract of the test matrix of the Carrier cabinet with base CU as shown
annex 2).
Test no
Room (m2) Release mass (g)
Cabinet Cabinet po-
sition Leak location
Condenser airflow
Evaporator airflow
Doors
1
10 150 Base CU
(C) Narrow end,
centre
Evap return bends
Off Off None
2 Cond return
bends Off Off None
Test no Kick-plates CU cover Roof cover Mass flow
(g/min) Release time (s)
Measure-ment time
[min] Remark
1 None None None 30
5 14
Overall baseline
2 None None None 30 Overall baseline
Table 1) Extract test 1 & 2 of the test matrix of the Carrier cabinet with base CU
With these settings test 1 (and 2) were performed. Sensors were positioned (see fig. 2) and
numbered as shown in figure 3.
Figure 3) Numbering of the sensor positions
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The according data for the first 3 min at measurement point 1 (MP 1) are listed in tab. 2. At
MP 1 (0.5 m distance to the cabinet) IR sensor 1 was detecting the R290 concentration in
parallel with a thermal conductivity sensor (FTC5).
Table 2) Extract measurement results of test 1 (Carrier cabinet with base CU)
The resulting curve of the concentration (expressed in percent of the LFL) against time for IR
sensor 1 is plotted in figure 4a. The plot of the comparable curve from thermal conductivity
sensor FTC5 is shown in fig. 4b.
Hour DurationMass flow controller
V set [l/min]
Mass flow controller
V as-is [l/min]
IR sensor [%UEG]
Measurement Point 1
FTC5@MP 1
[%UEG]
10:50:01 00:00:01 0 0,1 0 0
10:50:06 00:00:06 0 0,1 0,1 0
10:50:11 00:00:11 0 0,1 0,1 0
10:50:16 00:00:16 0 0,1 0 0
10:50:21 00:00:21 0 0,1 0,1 0
10:50:26 00:00:26 0 0,1 -0,1 0
10:50:31 00:00:31 15 0,1 0 0
10:50:36 00:00:36 15 14,8 0 0
10:50:41 00:00:41 15 15,1 0,1 0
10:50:46 00:00:46 15 15,2 0,1 0
10:50:51 00:00:51 15 15,2 0 0
10:50:56 00:00:56 15 15 0 0
10:51:01 00:01:01 15 15 0,1 1
10:51:06 00:01:06 15 15 0 3
10:51:11 00:01:11 15 15,1 -0,1 6
10:51:16 00:01:16 15 15 0,9 10
10:51:21 00:01:21 15 15,1 3,4 13
10:51:26 00:01:26 15 15 5,4 18
10:51:31 00:01:31 15 15,2 7,1 26
10:51:36 00:01:36 15 15,3 9,4 31
10:51:41 00:01:41 15 15,1 12,7 30
10:51:46 00:01:46 15 15,2 15,3 30
10:51:51 00:01:51 15 15 18,3 33
10:51:56 00:01:56 15 15,1 22,4 35
10:52:01 00:02:01 15 15,1 26 36
10:52:06 00:02:06 15 15,1 28 38
10:52:11 00:02:11 15 15 30 39
10:52:16 00:02:16 15 15,1 31,3 38
10:52:21 00:02:21 15 15,1 33,5 40
10:52:26 00:02:26 15 15 34,7 41
10:52:31 00:02:31 15 15,1 35,4 43
10:52:36 00:02:36 15 15,1 35,8 43
10:52:41 00:02:41 15 15,1 36,8 43
10:52:46 00:02:46 15 15 37,5 41
10:52:51 00:02:51 15 15 39,7 40
10:52:56 00:02:56 15 14,8 40 42
10:53:01 00:03:01 15 15,1 41,4 43
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Figure 4) Concentration time curve of the leakage simulation test 1 (IR sensor 1)
Figure 4b) Concentration time curve of the leakage simulation test 1 (FTC sensor 5)
As can be seen from tab. 2 after 31 s the mass flow controller was switched to 15 l/min re-
lease of R290 (V set [l/min]). After the next time step of 5 s it was indicated that this flow was
realized (V as-is [l/min] with a value of 14.8 l/min). After further 25 s R290 is indicated from
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the thermal conductivity detector FTC5 (00:01:01) with a rough value of 1 % LFL. After fur-
ther 15 s IR sensor 1 is indicating R290, too (00:01:16 with 0.9 % LFL).
Comparing the concentration values of both sensor types (fig. 4a & b) shows advantages
and disadvantages of both sensor types. The thermal conductivity detector reacts faster to a
change of the gas concentration. The IR sensor shows a delayed increase and decrease due
to a membrane around the measurement cell which is necessary for explosion protection of
this sensor. An advantage of the IR sensor is the higher sensitivity (smother curve) and lower
detection limit. Another disadvantage is a technical set for an upper detection limit at beneath
100 % LFL. The FTC sensor is not restricted to the 100 % LFL level and was therefore, used
at critical measurement points as sensor type to measure concentration far above the 100 %
LFL level.
After 5 min release time the R290 release in the cabinet was stopped. 10 min after starting
the test the air of the tent was extracted and exhausted to the outside of the test hall. This
can be seen in fig. 5 for the concentration time curves of all sensors. 13 min after starting
test 1 all measurements were stopped.
Figure 5) Concentration time curves of the leakage simulation test 1 (all sensors)
Especially for lower concentrations (below 30 % LFL) the IR sensor is more precise than the
FTC.
To examine the risk potential by potential leakages in a cabinet in closed rooms the meas-
ured concentration times curves in dependence of the location in the tent are very valuable.
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4.2 Repeatability of the R290 concentration measurements
To examine the repeatability of this test method several tests under same conditions were
repeated. For this examination in the 20 m² tent a diffusor was placed and R290 released.
Pictures of this diffusor are shown in pic. 10a & b and for the test setup in pic. 10c & d.
Pic. 10a) Diffusor setup: bottom of the bucket
with holes for equal gas release
Pic. 10b) Diffusor setup: bucket with cotton as
diffusor material; in the centre a
smaller jar in which the tube to the
R290 pipe is connected
Pic. 10c) Diffusor hanging at a stand
Pic. 10d) Diffusor located at the narrow wall of
the 20 m² room; sensors placed
according scheme fig. 6
The scheme of the sensor positioning for this diffusor test is shown below in figure 6.
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Figure 6) Scheme of the diffusor test setup
The according measurement schedule is shown in table. 3.
Table 3) Test schedule of the repeatability test with the diffusor
The data for all 4 test runs for one measurement point or location are shown in comparison in
the following figures 7a to 7g for several measurement points (MP).
Sensors from MP1 to MP10 are type infrared (IR) and MP 11 & 12 thermal conductivity
(FTC).
Differences between the scatter of the curves of the four repeated runs may derive from the
sensor type and distance from the diffusor (release point), position and height in the room.
To examine this for all sensors at the different measurement points the average at a time
point where roughly a 50 % LFL value occurs were selected. For this moment beneath the
average the standard deviation and the relative standard deviation were calculated (Tab. 4).
Test no Room (m 2)Release mass
(g)Unit
Unit base
install heightUnit position
-1 20 1500 Diffusor 1.8 mBroad wall,
middle
Test no Leak location Unit airflow LouvreMass flow
(g/min)Remarks
-1 Diffusor Off - 60Repeatablity: 4
x (-1/1 to -1/4)
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Figure 7a) Four concentration-time curves of the diffusor test at MP 1 (0.5 m from diffusor)
Figure 7b) Four concentration-time curves of the diffusor test at MP 5 (1 m from diffusor)
Figure 7c) Four concentration-time curves of the diffusor test at MP 7 (2 m from diffusor)
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Figure 7d) Four concentration-time curves of the diffusor test at MP 9 (4.5 m from diffusor)
Figure 7e) Four concentration-time curves of the diffusor test at MP 10 (5 m from diffusor)
Figure 7f) Four concentration-time curves of the diffusor test at MP 11 (2.5 m from diffusor)
Start air ex-haust of tent
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Figure 7g) Four concentration-time curves of the diffusor test at MP 12 (2.5 m from diffusor)
Table 4) Comparison of the scatter (RSD) between different measurement points
A comparison of the data in tab. 4 gives no clear answers. It seems to be that the sensors
positioned nearer to the diffusor (MP 5 & 1) have less scatter than for MP 9 & 10. This be-
comes clearer comparing the curves (7a & b with 7d & e). MP 7 shows in tab. 4 a quite high
RSD (20 %). But this is caused by a strong deviation of the curve from run 3 (MP 7-3) in fig.
7c. After reaching values of > 60 % LFL after 3 min the scatter is quite low between the dif-
ferent curves.
The different concentration-time curves from MP 11 (FTC sensor) are showing a higher scat-
ter below 80 % LFL (tab. 4 23 % RSD after 15 min) but are approaching quite similar values
after 20 min. Only MP 12 which is positioned 2 m above floor level shows especially after 20
min an increasing scatter. This is probably caused by fluctuating R290 levels in that height.
After 30 min the R290 loaded air was extracted from the tent.
Measurement
PointSensor type
Distance to release
point [m] / Height [m]
Average
point in time
Average [%
LFL]
Standard deviation
[% LFL]
Relative standard
deviation [%]
1 IR 0,5/0 2 min 46,7 6,4 14
5 IR 1/0 3 min 53,0 3,8 7
7 IR 2/0 2 min 50,8 9,9 20
9 IR 4,5/0 5 min 51,6 7,9 15
10 IR 5/0 7 min 53,1 7,8 15
11 FTC 2,5/1 15 min 51,3 12,0 23
12 FTC 2,5/2 25 min 17,5 5,7 32
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In the figures 7a to 7e all IR sensors are showing a mixture between a flat line and a “squig-
gle” reaching the 100 % LFL level. This irregular behaviour of the IR gas sensors during the
R290 measurement has a technical reason.
As this IR sensor is designed to be used as a stationary sensor for gas monitoring it would
not regularly face gas concentrations higher than 100%. But the very high resolution and pre-
cision beneath the ATEX certificate were the reasons to use this detector. Due to an alarm-
control it will set its analogue output to a value below 0% (e.g. to switch on an alarm horn).
To prevent this behaviour DMT reprogramed the measurement software, so values below
0 % appear as 100 % to keeps the concentration at the upper limit. Because the sensor is
quite slow it is very difficult for the software to clearly identify this case, so a “jumping” or
“squiggle” appears at concentrations near 100%.
4.3 Presentation of all test results
In annex 1 the measurement matrix for the Top CU multideck cabinet is shown. The accord-
ing concentration time curves of all room positions summarized for one test run in a graph
are shown for all these test runs in annex 3 (figure 8a from test no. 17 to fig. 8ab from test
no. 47).
The comparable graphical presentation of all test results as concentration time curves for the
Base CU cabinet (matrix from annex 2) are shown in annex 4 (figure 9a from test no. 1 to fig.
9v from test no. 50).
Report No. Date Page
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5 Summary
In this report the testing conditions for simulated leakage tests with multideck cabinets are
described.
All tests were performed under strict safety regulations and precautions because R290 is
a highly flammable refrigerant. Despite the limitations caused thereby and especially in
view of the sensor systems which can be used as online monitoring system, the resulting
data could be used as expected for a subsequent risk assessment of cabinets for usage
with several hundreds of gram of R290.
Essen, June 21, 2016
_______________________________ _________________________________
Dr. D. Renschen S. Roeser
(Head Product Assessment Refrigeration & Air Quality) (Technician Product Assessment Air Quality)
Report No. Date Page
APS 2 00 005 16 2016/09/30 34/63
Annex 1a
Measurement Matrix Top CU (A)
Te
st
no
Ro
om
(m2)
Re
lea
se
ma
ss
(g
)C
ab
ine
tC
ab
ine
t
po
sit
ion
Le
ak
loc
ati
on
Co
nd
en
se
r
air
flo
w
Ev
ap
ora
tor
air
flo
wD
oo
rsK
ick
-
pla
tes
CU
co
ve
rR
oo
f
co
ve
r
Ma
ss
flo
w
(g/m
in)
Re
lea
se
tim
e (
s)
Me
as
ure
m
en
t ti
me
[min
]
Re
ma
rk
17O
ffO
ffO
pen
On
On
Off
30
18O
ffO
ffO
pen
Off
On
Off
30
19O
ffO
ffO
pe
nO
n*
On
Off
10-
20
Off
Off
Clo
se
dO
n*
On
Off
10-
21
Off
Off
Clo
se
dO
n*
On
Off
30
Th
e t
wo
do
ors
in
th
e m
idd
le o
pe
ne
d 1
min
aft
er
lea
ka
ge
; F
an
sta
rte
d 4
:30
min
la
ter
22
Off
On
Clo
se
dO
n*
On
Off
30
-
23
Off
On
Op
en
On*
On
Off
30
-
24
On
Off
Open
On*
On
Off
30
Eff
ect o
f co
nd a
irflo
w o
n le
ak fro
m e
va
p
25
On
(x
1)O
ffC
lose
dO
n*
On
Off
60
18,0
Fa
n #
3 o
n (th
is c
abin
et h
as 6
co
nde
nse
r fa
ns)
26
On
(x
2)
Off
Clo
se
dO
n*
On
Off
60
19,0
Fa
ns #
2 +
#5
on
27
On
(x
3)
Off
Clo
se
dO
n*
On
Off
60
20,0
Fa
ns #
1 +
#4
+ #
6 o
n
On
(x
4)
Off
Clo
se
dO
n*
On
Off
60
- (W
as n
ot d
on
e b
eca
use
pre
vio
us te
st C
f < 12
g/m
3)
28
Off
Off
Clo
se
dO
n*
On
Off
1050
60
-
29
Off
Off
Clo
se
dO
n*
On
Off
30
16,7
30
-
30
Off
Off
Clo
se
dO
n*
On
Off
60
8,3
18-
31
Off
Off
Clo
se
dO
n*
Off
Off
30
-
32
Off
Off
Clo
se
dO
n*
Off
On
30
-
33
Off
Off
Clo
se
dO
n*
On
On
30
-
34
Off
Off
Clo
se
dO
n*
On
Off
30
Ad
d p
oly
sty
ren
e p
an
el t
o C
U c
orn
er to
div
ert
35
Off
Off
Clo
se
dO
n*
On
Off
30
-
37
Co
nd
en
se
r
retu
rn
be
nd
s
Off
Off
Clo
se
dO
n*
On
Off
30
30
-
36
Ro
om
ce
ntr
eC
U h
ou
sin
gO
ffO
ffC
lose
dO
n*
On
Off
30
Mo
ve
to
ce
ntr
e o
f ro
om
(se
e te
st w
ith
to
p C
U C
)
16,7
20
500
top
CU
(A)
Bro
ad s
ide
,
ce
ntr
e
Eva
po
rato
r
retu
rn b
en
ds
CU
ho
usin
g
8,3
16,7
25,0
30,0
Ma
trix
To
p C
U
De
term
ine
kic
k-p
late
ca
se
with
th
e h
ighe
st C
f
50
60
16,7
30,0
Report No. Date Page
APS 2 00 005 16 2016/09/30 35/63
Annex 1b
Measurement Matrix Top CU (A)
Te
st
no
Ro
om
(m2)
Re
lea
se
ma
ss
(g
)C
ab
ine
tC
ab
ine
t
po
sit
ion
Le
ak
loc
ati
on
Co
nd
en
se
r
air
flo
w
Ev
ap
ora
tor
air
flo
wD
oo
rsK
ick
-
pla
tes
CU
co
ve
rR
oo
f
co
ve
r
Ma
ss
flo
w
(g/m
in)
Re
lea
se
tim
e (
s)
Me
as
ure
m
en
t ti
me
[min
]
Re
ma
rk
38
Off
Off
Open
On*
On
Off
1010
012
0-
39
Off
Off
Open
On*
On
Off
30
50
-
40
Off
On
Open
On*
On
Off
30
50
-
41
On
(x3
)O
ffC
losed
On*
On
Off
60
45
(i) S
tart
with m
ax
no
fans fro
m 2
0 m
2 ro
om
.
(Fans #
1 +
#4 +
#6 o
n)
42
On
(x 4
)O
ffC
losed
On*
On
Off
60
30
(ii) If
Cf < 12 g
/m3, t
hen d
o test w
ith o
ne few
er fa
n. B
ut if
Cf > 12 g
/m3, t
hen d
o test w
ith o
ne m
ore
fan.
(Fans #
1 +
#3 +
#4 +
#6 o
n)
43
Off
Off
Clo
sed
On*
On
Off
1010
011
0-
44
Off
Off
Clo
sed
On*
On
Off
30
33,3
50
-
45
Off
Off
Clo
sed
On*
On
Off
60
16,7
31
-
46
Ev
ap
ora
tor
retu
rn
be
nd
s
Off
Off
Op
en
On*
On
Off
30
-
47
Co
nd
en
se
r
retu
rn
be
nd
s
Off
Off
Clo
se
dO
n*
On
Off
30
-
Ma
trix
To
p C
U
750
33,3
38
1000
top C
U
(A)
Bro
ad s
ide,
centr
e
Evapo
rato
r
retu
rn b
ends
33,3
Co
ndenser
retu
rn b
ends
16,7
40
Report No. Date Page
APS 2 00 005 16 2016/09/30 36/63
Annex 2
Measurement Matrix Base CU (C) T
es
t n
oR
oo
m
(m2)
Re
lea
se
ma
ss
(g
)C
ab
ine
tC
ab
ine
t
po
sit
ion
Le
ak
loc
ati
on
Co
nd
en
se
r
air
flo
w
Ev
ap
ora
tor
air
flo
wD
oo
rsK
ick
-
pla
tes
CU
co
ve
rR
oo
f
co
ve
r
Ma
ss
flo
w
(g/m
in)
Re
lea
se
tim
e (
s)
Me
as
ure
m
en
t ti
me
[min
]
Re
ma
rk
1E
va
p r
etu
rn
be
nd
sO
ffO
ffN
on
eN
on
eN
on
eN
on
e30
Ove
rall
ba
se
line
2C
on
d r
etu
rn
be
nd
sO
ffO
ffN
on
eN
on
eN
on
eN
on
e30
Ove
rall
ba
se
line
3O
ffO
ffN
on
eN
on
eN
on
eN
on
e10
30
39
-
4O
ffO
ffN
on
eN
on
eN
on
eN
on
e3
020
-
5O
ffO
nN
on
eN
on
eN
on
eN
on
e30
22
-
6a
On
(x
1)O
ffN
on
eN
on
eN
on
eN
on
e6
0 F
an
#3
on
6b
Off
Off
No
ne
No
ne
No
ne
No
ne
60
Fa
ns o
ff
7O
n (
x 2
)O
ffN
on
eN
on
eN
on
eN
on
e60
Fa
sn
#3
+ #
2 o
n
8O
n (
x 3
)O
ffN
on
eN
on
eN
on
eN
on
e60
Fa
ns #
1 +
#3
+ #
4 o
n;
On
ly d
o if
pre
vio
us te
st C
f >
15
g/m
3
9a
Off
Off
No
ne
No
ne
No
ne
No
ne
30
Ca
rdb
oa
rd b
ox
on
to
p o
f ca
bin
et to
sim
ula
te C
U
9b
Off
Off
No
ne
No
ne
No
ne
No
ne
30
Mo
ve
re
ar fr
om
wa
ll 3
× m
in d
ista
nce
(3
0 c
m)
9c
Ro
om
ce
ntr
eO
ffO
ffN
on
eN
on
eN
on
eN
on
e30
Mo
ve
to
ce
ntr
e o
f ro
om
10O
ffO
ffN
on
eN
on
eN
on
eN
on
e10
50
60
-
11O
ffO
ffN
on
eN
on
eN
on
eN
on
e3
03
0,0
-
12O
ffO
nN
on
eN
on
eN
on
eN
on
e30
-
13O
n (
x1)
Off
No
ne
No
ne
No
ne
No
ne
60
Fa
n #
3 o
n (If C
f >
12
g/m
3, t
he
n d
o te
st w
ith
on
e m
ore
fan
. (I.e
., m
ax
2 te
sts
))
14O
n (x
2)
Off
No
ne
No
ne
No
ne
No
ne
60
-
153
00
Off
Off
No
ne
No
ne
No
ne
No
ne
30
10-
167
50
Off
Off
No
ne
No
ne
No
ne
No
ne
30
25
-
48
20
50
Off
Off
Open
No
ne
--
30
1,7
10
49
75
0O
ffO
ffO
pen
No
ne
--
60
12,5
25
50
100
Off
Off
Open
No
ne
--
60
1,7
1214
10
Co
nd
en
se
r
retu
rn b
en
ds
5
1015
0B
ase
CU
(C)
Na
rro
w e
nd
,
ce
ntr
e5
10300
ba
se
CU
(C)
Na
rro
w e
nd
,
ce
ntr
e
Eva
po
rato
r
retu
rn b
en
ds
20
500
ba
se
CU
(C)
Na
rro
w e
nd
,
ce
ntr
e
Eva
po
rato
r
retu
rn b
en
ds
16
Mo
ck
to
p-
mo
un
ted
CU
1020
16,7
ba
se
CU
(Ca
rrie
r)
Na
rro
w e
nd
,
ce
ntr
e
Co
nd
en
se
r
retu
rn b
en
ds
-40
Ma
trix
Ba
se
CU
Co
nd
en
se
r
retu
rn b
en
ds
8,3
20
,0
Eva
po
rato
r
retu
rn b
en
ds
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Annex 3
Graphical presentation of all tests made with the Top CU cabinet
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APS 2 00 005 16 2016/09/30 38/63
Figure 8a – Test CabA17
Figure 8b – Test CabA18
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Figure 8c – Test CabA19
Figure 8d – Test CabA20
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Figure 8e – Test CabA21
Figure 8f – Test CabA22
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Figure 8g – Test CabA23
Figure 8h – Test CabA24
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Figure 8i – Test CabA25
Figure 8j – Test CabA26
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Figure 8k – Test CabA27
Figure 8l – Test CabA28
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Figure 8m – Test CabA29
Figure 8n – Test CabA30
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Figure 8o – Test CabA31
Figure 8p – Test CabA32
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Figure 8q – Test CabA33
Figure 8r – Test CabA37
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Figure 8s – Test CabA38
Figure 8t – Test CabA39
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Figure 8u – Test CabA40
Figure 8v – Test CabA41
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Figure 8w – Test CabA42
Figure 8x – Test CabA43
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Figure 8y – Test CabA44
Figure 8z – Test CabA45
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Figure 8aa – Test CabA46
Figure 8ab – Test CabA47
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Annex 4
Graphical presentation of all tests made with the Base CU cabinet
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Figure 9a – Test CabB1
Figure 9b – Test CabB2
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Figure 9c – Test CabB2b
Figure 9d – Test CabB3
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Figure 9e – Test CabB4
Figure 9f – Test CabB5
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Figure 9g – Test CabB6
Figure 9h – Test CabB6b
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Figure 9i – Test CabB7
Figure 9j – Test CabB8
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Figure 9k – Test CabB9
Figure 9l – Test CabB9b
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Figure 9m – Test CabB9c
Figure 9n – Test CabB10
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Figure 9o – Test CabB11
Figure 9p – Test CabB12
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Figure 9q – Test CabB13
Figure 9r – Test CabB15
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Figure 9s – Test CabB16
Figure 9t – Test CabB48
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Figure 9u – Test CabB49
Figure 9v – Test CabB50