Agriculture Reference
In-Depth Information
during transportation, retail distribution and home storage to maintain the
foods at the desired temperatures. These are important steps in maintain-
ing the safety, quality and shelf life of foods for the consumer, and the
processes from primary cooling through to domestic storage make up the
'food cold-chain.' If climatic change results in a substantial rise in average
ambient temperatures this will impose higher heat loads on all systems in
the cold-chain. In systems that have capacity to cope with these higher
loads this will just require the refrigeration plants to run for longer periods
and use more energy (James and James, 2010). In addition to the genera-
tion of CO
2
the refrigerants currently used in cold-chain have considerable
global warming potential (GWP). Use of alternative refrigerants and alter-
native refrigeration cycles with a reduced GWP is need of our.
About 20% of the global-warming impact of refrigeration plants is due
to refrigerant leakage. The dominant types of refrigerant used in the food
industry in the last 60 years have belonged to a group of chemicals known
as halogenated hydrocarbons, for example, chlorofluorocarbons (CFCs)
and the hydrochlorofluorocarbons (HCFCs). Scientific evidence clearly
shows that emissions of CFCs have been damaging the ozone layer and
contributing significantly to global warming. The little data that is avail-
able suggests that currently the cold-chain accounts for approximately 1%
of CO
2
production in the world. However this is likely to increase if global
temperatures increase significantly. Until recently the major concern in
the refrigeration industry regarding climate change has been the impact of
refrigerants on the ozone layer and the replacement of current refrigerants
with “greener” alternatives. Energy efficiency is increasingly of concern
to the food industry mainly due to substantially increased energy costs
and pressure from retailers to operate zero carbon production systems.
Reducing energy in the cold-chain has a big part to playsince worldwide
it is estimated that 40% of all food requires refrigeration and 15% of the
electricity consumed worldwide is used for refrigeration. Simple solutions
such as the maintenance of food refrigeration systems will reduce energy
consumption. Repairing door seals and door curtains, ensuring that doors
can be closed and cleaning condensers produce significant reductions in
energy consumption. In large cold storage sites it has been shown that
energy can be substantially reduced if door protection is improved, pe-
destrian doors fitted, liquid pressure amplification pumps fitted, defrosts
optimized, suction liquid heat exchangers fitted and other minor issues
corrected.
