FEATURE
INCORPORATING COLD CHAIN
(the CRS holding company). “The site is
relatively new and therefore the plant
has run for only a few months and while
the initial indicators currently show good
performance levels, we will continue to
monitor the consumption,” said Robinson.
Food Lovers Market’s first transcritical
CO 2 store recently opened in Randburg,
Johannesburg. The retail store has
traditionally gone with synthetic
refrigerant systems. However, after
much discussion with the CRS team
about the advantages of CO 2 , including
being a future-proof solution, they
decided to go for the CO 2 transcritical
booster system. This was a good time
for Food Lovers to get their foot in the
door with regards to having the latest
technology on the market.
“The job was the right size to go CO 2 ,”
explains Robinson. “It was a cost-effective
option and also fitted in with the Food
Lovers sustainability programme that
is heading to a more environmentally
friendly way forward,” he says.
Food Lovers is very proud of this pilot
project. According to Arthur Woest,
project manager for Food Lovers, “The
system is quiet, manageable from a
central point, and all data can be easily
collated, therefore feedback collected
can assist with preventing any potential
liabilities that can result in stock loss.”
Pick ‘n Pay installed an ammonia/
CO 2 cascade system in three stores in
different parts of the country nearly 10
years ago. In 2009, German development
agency, GTZ (now GIZ), funded the three
ammonia/ CO 2 cascade installations in
South Africa for PnP at stores based in
Strand, Rand Park Ridge and Hurlingham,
which came online in that order.
The PnP Strand, located in the
Western Cape province, near Cape
42
www.coldlinkafrica.co.za
Town, installed a NH 3 / CO 2 cascade
system with a secondary circuit (water/
glycol) for medium-temperature loads.
The ammonia part of the system uses
open-drive reciprocating compressors
and an evaporative condenser.
A similar system is used at PnP Rand
Park Ridge in Johannesburg. The only
difference was that the medium-
temperature and low-temperature loads
varied slightly between the two stores.
Both were retrofits of F-gas systems.
“Applying a TEWI [total equivalent
warming impact] view and looking at the
refrigerant’s direct GWP figures, this type
of installation is cleaner than a similarly
sized transcritical installation,” explains
Marius La Grange, manufacturing
manager at Energy Partners Refrigeration
Solutions. “When considering indirect
emissions from the energy consumed to
operate the plant, this type of installation
is also highly likely to come out on top.”
Ammonia is the most energy-efficient
solution for medium-temperature
applications "by some margin,” he said.
The CO 2 low-temperature system is also
operating within a set of operating
conditions where it is very energy
efficient, he adds. Then, of course,
there is the added bonus of zero ODP
and a GWP of only 1. In both cases,
the charge of the refrigerant was
very limited. With no recorded energy
consumption from the F-gas system
before the revamp, the reduced energy
consumption could not be verified. “But
we believe that the new installation
saved significantly on the electricity bill
the store had,” says La Grange.
He estimated that the installation
would offer a 30% or higher rate of
saving in energy consumption over
an HFC-charged DX installation.
“Maintaining an ammonia system is
more costly than an HFC system, but the
saving in operational costs offset that
additional cost by some margin.”
The medium-temperature air coolers
(heat exchangers) that were made
to fit into the cabinets and rooms
have a very low delta T (temperature
difference between the coolant and
the air temperature). This offers a few
advantages. “One of the biggest is the
fact that very little ice build-up on the
outside of the air coolers takes place,”
explains La Grange.
THE GOODS
In addition to the industry’s awareness of
the need for more training when working
with CO 2 , the need for products specific
to that refrigerant are needed.
Drawing attention to that factor
is Westermeyer Industries of Bluffs, Illinois.
It issued a press release announcing
that it had expanded its product line to
incorporate “a full line of code approved
high-pressure components supporting
operating pressures of transcritical CO 2
systems.”
The product line includes oil
separators, oil reservoirs, accumulators,
and receivers.
“We are constantly striving to meet
our customers’ needs and fulfil the
needs of the refrigeration industry,” says
company founder Gary Westermeyer.
“Our transcritical products help our
customers provide an environmentally
friendly system to the end user, thereby
meeting green initiatives.” CLA
REFERENCES:
Supermarkets around the world have taken the first step in reducing their carbon footprint
using natural refrigerants.
1.
2.
3.
4.
5.
6.
7.
ACHR News
R774.com
Accelerate.com
Yahoo Finance
Raca Journal
Supermarket News
Cooling Post
COLD LINK AFRICA •
March/April 2020