Determination of concentration time curves of the

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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

[email protected]

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

Report No. Date Page

APS 2 00 005 16 2016/09/30 2/63

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


Pic. 8b) Cabinet Top CU with CRB

(condenser return bend) RH


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


APS 2 00 005 16 2016/09/30 32/63

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).


APS 2 00 005 16 2016/09/30 33/63

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)


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


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


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


APS 2 00 005 16 2016/09/30 37/63

Annex 3

Graphical presentation of all tests made with the Top CU cabinet


APS 2 00 005 16 2016/09/30 38/63

Figure 8a – Test CabA17

Figure 8b – Test CabA18


APS 2 00 005 16 2016/09/30 39/63

Figure 8c – Test CabA19

Figure 8d – Test CabA20


APS 2 00 005 16 2016/09/30 40/63

Figure 8e – Test CabA21

Figure 8f – Test CabA22


APS 2 00 005 16 2016/09/30 41/63

Figure 8g – Test CabA23

Figure 8h – Test CabA24


APS 2 00 005 16 2016/09/30 42/63

Figure 8i – Test CabA25

Figure 8j – Test CabA26


APS 2 00 005 16 2016/09/30 43/63

Figure 8k – Test CabA27

Figure 8l – Test CabA28


APS 2 00 005 16 2016/09/30 44/63

Figure 8m – Test CabA29

Figure 8n – Test CabA30


APS 2 00 005 16 2016/09/30 45/63

Figure 8o – Test CabA31

Figure 8p – Test CabA32


APS 2 00 005 16 2016/09/30 46/63

Figure 8q – Test CabA33

Figure 8r – Test CabA37


APS 2 00 005 16 2016/09/30 47/63

Figure 8s – Test CabA38

Figure 8t – Test CabA39


APS 2 00 005 16 2016/09/30 48/63

Figure 8u – Test CabA40

Figure 8v – Test CabA41


APS 2 00 005 16 2016/09/30 49/63

Figure 8w – Test CabA42

Figure 8x – Test CabA43


APS 2 00 005 16 2016/09/30 50/63

Figure 8y – Test CabA44

Figure 8z – Test CabA45


APS 2 00 005 16 2016/09/30 51/63

Figure 8aa – Test CabA46

Figure 8ab – Test CabA47


APS 2 00 005 16 2016/09/30 52/63

Annex 4

Graphical presentation of all tests made with the Base CU cabinet


APS 2 00 005 16 2016/09/30 53/63

Figure 9a – Test CabB1

Figure 9b – Test CabB2


APS 2 00 005 16 2016/09/30 54/63

Figure 9c – Test CabB2b

Figure 9d – Test CabB3


APS 2 00 005 16 2016/09/30 55/63

Figure 9e – Test CabB4

Figure 9f – Test CabB5


APS 2 00 005 16 2016/09/30 56/63

Figure 9g – Test CabB6

Figure 9h – Test CabB6b


APS 2 00 005 16 2016/09/30 57/63

Figure 9i – Test CabB7

Figure 9j – Test CabB8


APS 2 00 005 16 2016/09/30 58/63

Figure 9k – Test CabB9

Figure 9l – Test CabB9b


APS 2 00 005 16 2016/09/30 59/63

Figure 9m – Test CabB9c

Figure 9n – Test CabB10


APS 2 00 005 16 2016/09/30 60/63

Figure 9o – Test CabB11

Figure 9p – Test CabB12


APS 2 00 005 16 2016/09/30 61/63

Figure 9q – Test CabB13

Figure 9r – Test CabB15


APS 2 00 005 16 2016/09/30 62/63

Figure 9s – Test CabB16

Figure 9t – Test CabB48


APS 2 00 005 16 2016/09/30 63/63

Figure 9u – Test CabB49

Figure 9v – Test CabB50

Documents

Determination of concentration time curves of the