| Abstract: |
Environmental considerations have led to the phase out of chlorofluorocarbon
(CFC) refrigerants from the domestic refrigeration industry. One intriguing
aspect is that the chlorine in CFCs is a good lubricating agent and any
deterioration of system performance may adversely influence other environmental
considerations. Based on the above, the aim of this research is to address
the sustainable development of domestic refrigeration systems using the
replacement refrigerant HFC-134a. The work focuses on the emissions that
may arise if the electrical consumption of the product deteriorates or
its durability is curtailed. Tribological characteristics on compressor
components influence both of these product attributes and therefore a
thorough system analysis was carried out. An in-house built experimental
test rig, which monitored slight variations in the electrical power drawn
by a reciprocating hermetic compressor, was used under different experimental
conditions. Furthermore, a detailed life cycle assessment on a domestic
refrigerator was performed to help quantify the ensuing environmental
burdens. In this way, a relation between tribological characteristics,
power consumption and environmental impact was studied. Results have shown
that the CFC substitute will increase friction and wear characteristics
on the aluminium alloy connecting rod and the steel gudgeon pin. These
characteristics led to an increase in the electrical energy consumption
of the compressor such that the indirect global warming implications are
set to rise with HFC-134a. If the sustainable development of this product
is to be ascertained then a change in refrigerants alone will not suffice.
New design considerations, primarily aimed at servicing and extending
the life of the hermetic compressor itself, are considered. This work
helps stimulate new ideas to address environmental issues influenced by
traditional engineering disciplines. For this reason additional future
research work, which will help determine these implications further, is
outlined. |