A New Standard for Refrigerated Vehicles

A New Standard for Refrigerated Vehicles
FRIGOBLOCK FK 25 SL
FRIGOBLOCK FK 25
The first edition of the German industrial standard DIN 8959 for the
technical requirements of insulated
vehicle bodies and their refrigeration
units was published in 1965. This
original edition was then used as the
basis for the international ATP-agreement for the cross-border transport
of perishable food signed in 1970. In
1981 DIN 8959 was reviewed to take
into account the practical experiences
gained by the leading temperature
controlled vehicle operators, bodybuilders and refrigeration equipment
manufacturers. For the first time the
refrigeration capacity requirements
for multi-drop distribution were laid
down. As over the years the 1981
edition proved to reflect quite well
the actual conditions of the refrigerated vehicle operators, in 1995,
again under the chairmanship of the
ATP-testing authority TUV Munich,
DIN 8959 was once more redrafted
and it now specifies certain criteria in
more detail taking into account the
technical developments that have
taken place since its first review in
1981.
FRIGOBLOCK FK 25 L
FRIGOBLOCK FK 13
FRIGOBLOCK FK 13L
Carrier Supra 950
FRIGOBLOCK FK 12
Thermoking TS 600
Thermoking TS 500
Carrier Supra 850
FRIGOBLOCK FK 11
Thermoking TS 300
Carrier Supra 750
W at 0°C
Thermoking TS 200
ATP refrigeration
capacities of the most
powerful overcab
refrigeration machines
W at -20°C
Carrier Supra 550
FRIGOBLOCK FK 8
Carrier Supra 450
0W
3000 W
6000 W
9000 W
12000 W
15000 W
18000 W
21000 W
24000 W
27000 W
FRIGOBLOCK HK 34 SL
FRIGOBLOCK HD 25
FRIGOBLOCK HK 25 SL
FRIGOBLOCK HK 25
Carrier Ultra
FRIGOBLOCK HK 24
Thermoking SL 400
For the first time the DIN 8959
December 95 edition requires to
consider the ageing of insulated
vehicle bodies in the calculation to
ascertain the required refrigeration
capacity. For the two following tables
an ageing factor of 1,3 for 6 years
and of 1,5 for 9 years has been used.
This k-value deterioration corresponds
to the experiences gained by the
various European ATP-test stations
with the especially well insulating CFCexpanded foam. However, since the
CFC-ban results on ageing so far
obtained are indicating that insulation
foam blown with non-CFC gases will
age even faster.
Carrier Vector
FRIGOBLOCK HK 25 L
FRIGOBLOCK HK 13
Thermoking SL 200
Carrier Maxima 1300
W at 0°C
FRIGOBLOCK HK 13 L
ATP refrigeration
capacities of the most
powerful trailer
refrigeration machines
W at -20°C
Carrier Maxima 1000
Thermoking SL 100
0W
3000 W
6000 W
9000 W
12000 W
15000 W
18000 W
21000 W
24000 W
27000 W
FRIGOBLOCK UK Limited,
Stowe Castle Business Park, Buckingham, MK18 5AB, Tel. +44 (0) 12 80 / 82 49 33, Fax 82 49 34, [email protected], www.frigoblock.com
03.05
FRIGOBLOCK Grosskopf GmbH
Postf. 11 02 39, 45332 Essen, Tel. +49 (0) 2 01 / 61 30 1–0, Fax 61 30 1–48, [email protected], www.frigoblock.com
The required refrigeration duty for
distribution vehicles is now specified
in more detail. Factors are laid down
for the additional refrigeration requirement caused by the air exchanges
when delivering to 2, 3, 4 or 5
customers per hour with door opening
times of max. 3 minutes each. In case
of a longer door opening time than 3
minutes other factors to compensate
for the door opening heat gain and
the reduced refrigeration unit run time
have to be used. As an example: for
one customer delivery per hour with
15 minutes door opening time the
factors for five customers per hour
with a max, 3 minutes door opening
time each are to be applied.
contain any reserves for cooling down
the body structure, refrigerating warm
empty return pallets or roll cages or
capacity required to reduce product
temperature. The required refrigeration capacity to precool an empty
vehicle body is, depending on its design, about 10 to 15 times higher than
the wall heat gain shown in the tables.
The reduction of the temperature of
frozen or deep-frozen products requires 4500 Watts refrigeration per ton
and per degree Celsius reduction, that
of chilled products above 0°C
8000 Watts per ton and degree Celsius.
All forced air transport refrigeration
units must be switched-off before the
vehicle doors are opened. Failure to
follow this important rule will result in
additional cold losses and the icingup of the evaporator coil. The specified factors for the remaining run time
of the refrigeration unit are to be
applied for units with their own dedicated combustion engine as well as
for units driven from the vehicle engine.
Refrigeration units driven from the
vehicle engine – as direct compressor,
hydraulic or alternator drive – must
supply the required refrigeration
capacities at max. 70% of the rated
vehicle engine speed. As per the new
DIN specification cold holdover systems
(eutectics, dry ice, nitrogen) must be
sized for a 10 hours delivery day. In
the past 4 hours was the accepted
standard.
During summer even with a ‘state of
the art’ loading over 20 to 30 minutes
from a non-refrigerated loading area
with dockshelters into a precooled
vehicle body deep-frozen products will
suffer a temperature rise of 2 to 3°C.
With open loading into a body that
has not been precooled a product
temperature rise of about 4 to 6°C
can be expected. As shown in the first
graph the frequent though short-time
door openings in deep-frozen multidrop distribution are causing unavoidable product temperature rises
of 5 to 1°C, even in vehicles specified
as per DIN 8959.
In order to compensate for these product temperature rises the journey
should be started with adequate product temperature reserves built-in in
the coldstore and after loading by
overnight mains standby operation of
a sufficiently powerful transport refrigeration unit.
Required refrigeration capacities
calculated as per DIN 8959 do not
30 wooden pallets 800 x 1200 mm, dry
30 wooden pallets 800 x 1200 mm, wet
30 corner metal reinforcements
à
440 Wh = 13.2 kWh
à 1900 Wh = 57.0 kWh
à
l70 Wh = 5.1 kWh
Heat content
22 wooden pallets 1000 x 1200 mm, dry à
22 wooden pallets 1000 x 1200 mm, wet à
à
22 corner metal reinforcements
600 Wh = 13.2 kWh of return
2600 Wh = 57.2 kWh
empties,
l80 Wh = 4.0 kWh
27 roll containers, dry
27 roll containers, wet
+20°C down
220 Wh = 5.9 kWh
750 Wh = 20.3 kWh to -20°C
à
à
cooling from